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Cardisoma sp. (likely C. armatum). Southeast Asia, Indonesia Land Crabs. Soap-Box Crabs for how they're individually shipped (in plastic soap-dishes closed with rubber bands) to prevent cannibalism. To eight inches across... Not a community tank item... Actually not totally aquatic... if you're lucky, yours will crawl out of the tank and leave.  Full Size Link

Updated 2/21/20, Ask us a question: Crew@WetWebMedia.com
Brackish INDEX to Articles and FAQs;
Other S
pecialized Daily FAQs Blogs: General,
Freshwater, Planted Tanks, Ponds,   
Daily Q&A replies/input from the WWM crew: 
Neale Monks, Marco Lichtenberger, Bob Fenner, are posted here. Moved about, re-organized into individual FAQs files!

Fish Issue ID      2/21/20
My GSP has developed some kind of growth on his right eye. Could you guys help me ID it and suggest a treatment for it? He also looks like he has an internal growth because he has this large hump on the right side around mid body.
Let me know if I could provide any more information to help ID this issue.
Thank you,
<Do read here:
If on the one eye, usually trauma, perhaps exacerbated by the environment; if on both eyes, disease more probable. The addition of Epsom salt (1-3 teaspoons per 5 gallons/20 litres) alongside the usual marine salt mix used in his brackish or marine system should provide some support, though the use of antibiotic may be helpful if there is signs of inflammation or dead tissue. Adult GSPs maintained in freshwater systems never stay healthy for long, so it's important to review the environment in any case: GSPs need moderately brackish to fully marine conditions; SG 1.010-1.025 at 25 C is about right. High levels of alkalinity and oxygen are both essential.
Cheers, Neale.>

Re: Fish Issue ID      2/21/20
Thanks for the quick response Neale. I'll get started with the Epsom salt.
<You're welcome. Cheers, Neale.>

Brackish tank mates       1/21/20
I'm a long-time patron of your website, and I have to say I really enjoy reading how passionate you all are and the entertaining delivery of the wealth of knowledge that you share. Thank you.
<And thanks for these kind words.>
I have a question regarding my 30 gallon brackish tank (I've had the brackish set up for around four years- SG 1.011/temp around 79F - I use instant ocean about one cup per 5 gallons and have a 90g canister filter running). I started with a swarm of BBGs and an SG of 1.005, then added a Knight Goby and some nerite snails. I've since slowly raised the SG and added a figure 8 puffer, Zebra hermit crab (they got along just fine!!) and nine Endlers. I knew the endlers would become food for the KG, but figured they would be fun to watch in the meantime(and fun for the KG- I have one left now). I apologize in advance if that seems cruel.
<I get cruelty is subjective, so will set that aside. The real issue is live feeder fish cause health problems. Firstly, they're an unknown quantity in terms of what parasites or bacteria they introduce into the fish that eat them. Wild fish can't really avoid this risk, and some (many, even) will be infected with parasites. But pet fish should be kept free of such parasites. Secondly, there's some anecdotal evidence that predators fed on live fish are apt to being more aggressive and/or predatory towards tankmates, while those that only see frozen or fresh foods don't acquire those traits to the same degree. Hunting down a few guppies doesn't really add anything to the life of your Knight Goby, so the argument that it
'enriches' their existence doesn't justify the potential health risks.>
Anyway, the BBGs have since passed away (might have been the increase in salinity or that they weren't great stock to begin with- though I had them for over 2 years).
<BBGs aren't really brackish water fish, despite their reputation. Some species do live in estuaries, it is true, but the farmed ones you see in pet shops are a fresh to low-end brackish species that does best with just a little salt, maybe SG 1.002-1.003. I've maintained them just fine in soft, slightly acidic conditions similar to those they inhabit in the wild.
They're actually more likely to starve to death than suffer from a water chemistry issue. BBGs are easily starved. They need decent sized meals, but resolutely ignore anything that's not fresh, live or frozen.>
I now have a tank with a figure 8 puffer, knight goby, two nerites, and one swordtail endler's livebearer. I realize I don't need the salinity so high and will likely back off slowly to around 1.008.
<If that; SG 1.003-1.005 is absolutely fine for this selection of livestock.>
The KG is very healthy but has gotten shy over the years, and mainly sticks to his preferred cave. The Figure 8 is very chill and has never shown any sign of aggression toward its tankmates.
<Yet, anyway!>
Here's the question: I'm thinking of adding some Desert Gobies if I can find them- like maybe two or three at most. If not, my brother has a bunch of Kribs and would be willing to give me three (I do not want to overstock my tank). What do you think about these two options given my tank setup?
<Kribs would only work at the lower salinity range, since they're not really brackish water fish. They inhabit the Niger Delta, for sure, so have some tolerance. SG 1.003 is not a problem, and they might even handle slightly more. But they're better in soft water with a neutral pH. Not only do their colours look much more intense, you also avoid the problem of just getting male fry (the ratio of males/females depends on pH, with 7 being 50/50, and above 7, increasingly more males and fewer females). As for
Desert Gobies, they simply don't belong here. Continual warmth will shorten their lifespan, and since they're basically annual fish, you want to keep a colony that's breeding otherwise you'll have none left after a few months (assuming you buy near-adults).>
I know Kribs get really aggressive when mating, but they would also add some great color contrast- If I got a group of females maybe they would be chill?
If neither option is good, I also wouldn't mind having a swarm of BBGs back in the tank but I fear the SG is too high.
<Perhaps, but I'm more concerned they'll be Knight Goby food, or else simply starve.>
What do you think?
<I'd be looking at more robust tankmates. Have you considered Etroplus maculatus? The wild-type is charming, if understated, while the all-orange farmed form is very colourful.>
Thanks for your response!
<Most welcome, Neale.>

Re: Brackish tank mates     1/22/20
Hello again!
<Hello Daniel,>
Thank you for your advice.
<Most welcome.>
Given your recommendations, I think I'll slowly lower the SG to the 1.003-1.005 range over the next few or more water changes.
<Sounds wise.>
Also, I've given up on the Desert Goby and Krib idea and will consider the Etroplus maculatus. I agree with you the wild-type are rather charming in their way.
<Yes; their colours change significantly with mood, as well as during breeding; there is another species called Etroplus suratensis that gets much bigger (around 15 cm/6 inches) but is very beautiful when kept
I think they could be a good addition to my tank. I also read that they eat algae, and would have no problem foraging in my tank in-between feedings. How many would you recommend?
<I would certainly keep a group; all Etroplus are social (if not actually schooling) fish and if kept in a reasonably big group, six or more, you'll avoid the territorial bullying you might get with pairs.>
I'm quite fond of my F8 puffer and KG. I want to make sure that they're getting enough good food to eat- I currently feed mostly frozen brine shrimp, krill, conch/urchin/marine worm cubes, soft-frozen reef caviar (bought mostly for the BBG but the F8 and KG like them too), and occasionally feed them super worms (large mealworms for reptiles sold at the pet store). The super worms provide some crunch for puff's teeth.
<Your fish seem to eat better than I do -- conch and caviare!>
Sometimes I give them bits of scallop and crushed mussels from the market- also good for puff's teeth. However, I've not had luck feeding my puffer snails- he just sucks them out of their shells and doesn't get the proper teeth grinding effect from crunching on them.
<Correct. Puffers are easily smart enough to select the least demanding way to gather food.>
I've trimmed the puffer's teeth twice now- using tricaine-s (ms 222) with baking soda to neutralize acidity- and that has been successful but I would like to keep his teeth trimmed naturally if possible. Do you have any ideas?
<Realistically, nope. While puffers presumably do keep their teeth trimmed in the wild, the reality is that we don't offer the sort of high-fibre, low-nutrient foods that would do that. You could try smearing prawn or fish onto a pumice stone, and he'd have to pick away at the rock to get some food. You can also try offering less processed and more whole invertebrates, the 'wholer' the better! Try offering steadily bigger and more robust foods -- cooked crayfish or king prawn legs initially, but scaling up to things like crab or lobster legs as budget allows.>
Lastly, in the past I've added live ghost shrimp to the tank and both the puffer and KG enjoyed the live snack. Is this a good idea?
<Yep, especially if gut-loaded with greens-based flake food first (such as Spirulina flake). On the other hand, crustaceans (as well as mussels) are high in thiaminase, which causes long term problems, so need to be a minority food (unless gut-loaded or vitamin-enriched) compared with white fish fillet, insects, snails, and cockles.>
I've attached two photos of my tank in case you're curious.
<Thanks for sharing!>
In one of the photos, all three fish came out to see what I was up to (KG is poking out of the cave in the back). Thank you again for taking the time to write back!
<And to you, best wishes, Neale.>

Red Claw Crab not Eating 12/29/19
Hello! Hardly anyone knows anything about red claw crabs, as I cannot find any answers as to why my red claw crab has stopped eating!
<Let's see if we can help.>
He is kept in brackish water conditions, has filtered water, and water that is always about 74 degrees Fahrenheit.
<Right. Let's review first. By "brackish", how salty are we talking about? The first thing you do when brackish water animals misbehave is change the salinity. Many if not most come from places where the salinity varies, so just making a change can have a positive effect. But the bigger issue is that you need to be using a substantial amount of salt, not the teaspoon per gallon amounts often mentioned. I'd suggest one teaspoon per litre (i.e., a salt concentration of about 6 gram/litre) to produce about one-sixth normal seawater salinity. If that didn't do the trick, feel free to double that amount, which would get you around one-third normal seawater salinity. Either of these would be much closer to real world situations for Perisesarma bidens. Next up, review air temperature. 23 C/74 F is very much towards the low end for a tropical animal, and I'd crank the water heater up to 25 C/ 77 F. In cold conditions tropical animals will slowly lose vigour, and loss of appetite is an extremely common symptom of that. Death invariably follows soon after, though it may take weeks to happen.>
He is able to climb to get air or be in water when he wants. I have sand substrate. When I first got him, he would eat his food fine, but now, he won’t eat at all. I noticed he wouldn’t eat, so I ended up putting his food right in front of him, and he still won’t eat that food.
<Loss of appetite in crabs is almost always a symptom of environmental problems. Review as stated above.>
I don’t think he’s molting, because he’s been acting this way for about 2 weeks and I was told molting should only take about a day.
<Correct, and moulting crabs tend to hide away. They do need a source of iodine to moult successfully, for which purpose either offer regular portions iodine-rich foods (Sushi Nori is ideal) or else specific iodine-enriched crustacean foods sold for use in marine aquaria.>
Also, I don’t think it’s a calcium problem, as I give him special vitamins that help provide him calcium every 3 weeks. I’m really worried about him, and I have no idea why he is not eating.
<Hope this helps. Cheers, Neale.>
Re: Red Claw Crab not Eating       1/1/2020

Thank you very much for this help! Right after I added more salt, he molted the next day.
Does he absolutely need to eat his exoskeleton? If so, he is not eating it.
<No, he doesn't need to eat it, but most crabs do, simply to recycle the calcium. If he doesn't, that's fine, but do add some suitable replacement, like a small shell-on prawn that he can pick apart and consume. Failing that, just dusting whatever he likes to eat (fish meat, banana, etc.) with crushed cuttlebone or even fragments of edible snail shells (escargot) will have the same usefulness. Some crab foods are calcium-enriched and may be good enough on their own, but personally, I'd make a point of offering
extra calcium immediately after moulting. Cheers, Neale.>
Re: Red Claw Crab not Eating   1/11/20

I’d like to thank you for helping me with my red claw crab. Unfortunately, he has passed away even after adding a proper amount of salt and turning up the temperature, as he just did not eat at all.
<I'm sorry to hear that.>
I don’t know the reason for his refusal to eat, but after taking your advice, he seemed to have more energy and would actually approach the food (but still didn’t eat it). Maybe he was sick?
<Indeed, or perhaps, he'd been away from salty water for too long. These are tricky animals to keep well -- they need brackish water, high humidity (cold or dry air quickly kills them), and food that contains all the nutrients including iodine and calcium. So while inexpensive in themselves, and not demanding in terms of space, they are tricky.>
I don’t know, but I’m glad I found your website and got some help. You are very knowledgeable about these creatures, and people who are having trouble with their pet crabs are fortunate enough to be able to contact you for help. Again, thank you very much.
<You are most welcome, and thanks for these kind words. Good luck with your next pet! Cheers, Neale.>

Damselfish Identification - Neopomacentrus; & BR use         11/20/19
Good evening,
<Hi Joel>
I was at a local fish store today and came across these two lovely looking Damselfish in the store's batch of "Assorted Damsels". I've only been keeping saltwater fish for a short period of time, but have sufficient experience in brackish fishkeeping to tentatively identify them as Freshwater Demoiselles (Neopomacentrus taeniurus). I've never seen them before in person and pictures online of the related N. cyanomos sometimes appear similar, so I was hoping you might be able to verify for me.
<These appear to be Neopomacentrus taeniurus>
Sadly, I don't think they are appropriate for either of my tanks. My 125 gallon brackish tank at 1.006 may be too "fresh" and may squabble with the 8 Orange Chromides in it. On the other hand, I'd worry that it would fight with my Talbot's Damsel in my 55 gallon saltwater.
In either case, just seeing this rare (to me) Damsel was enough of a treat.
Thank you for your time.
<Am going to ask Neale Monks here to respond re Pomacentrids for brackish systems. His background w/ such systems is extensive. Bob Fenner>
Re: Damselfish Identification - Neopomacentrus /Neale        11/20/19

Hello Bob, Joel,
Yep, agree with the identification of your damselfish as Neopomacentrus taeniurus, but with the cautious that there are other species, such as Stegastes otophorus, that do look quite similar (especially the yellow tail). That said, Neopomacentrus taeniurus does have a more deeply-forked tail, suggesting your initial identification may well be correct.
I’ve seen Neopomacentrus taeniurus kept in freshwater tanks where they had been in situ for at least six months, seemingly without harm. Companions including Corydoras catfish and Angelfish of all things, and while the water was certainly hard, it wasn’t salted. I suspect 1.006 will probably be tolerated perfectly well, as these are truly euryhaline fish rather than marine fish that happen to handle brackish water for longer or shorter periods (as would be the case with, for example, Sergeant Majors). In some places (including various oceanic Pacific islands) they inhabit completely freshwater habitats alongside classic peripheral freshwater fish types like Gobies that, in common with Neopomacentrus, have a marine reproductive stage but as adults inhabit freshwater environments. I believe Neopomacentrus taeniurus breed in the sea, however, rather than spawning in freshwater and leaving their eggs to drift into the sea. Hence finding Neopomacentrus taeniurus in freshwater, brackish, and fully marine habitats.
My understanding is that they’re often found in harbours, estuaries, and tidally-influenced rivers and streams, often quite murky ones (hence their drab colouration). Water depth is rarely very great (less than 3m by one source). Allen refers to them as dwellers of ‘inshore reefs’ so I guess your classic coastal rocky reefs with oysters and mangroves rather than offshore coral reefs seem to be their preferred habitat. My guess would be that they’re much like various Apogon and Gobiidae species that are found in such places: perfectly well adapted to varying salinity, able to handle low salinity, even freshwater, for extended periods, but probably happiest (in the sense of being able to spawn successfully) when kept in mid to high end brackish conditions or fully marine salinities.
They are planktivores by nature, but consume all the usual foods that you’d give small Damselfish.
I agree, Orange Chromides would likely be viewed as a competitor. There’s no particular reason you couldn’t accommodate both given sufficient hiding places, but you’d certainly want to plan ahead. I don’t know enough about Neopomacentrus generally to comment on their social behaviour towards other Damsels in a marine aquarium, but would imagine Neopomacentrus taeniurus are par for the genus. Possibly Bob can add more here.
<The genus is more toward the easygoing spectrum of damsel territoriality; not quite Chromis. I do consider, as you've stated re habitat, that they should co-exist w/ Chromides.>
That pretty much covers what I know! The problem is they’re hardly ever imported, and almost never kept in freshwater or brackish systems. I’m not aware of any long term records beyond what I’ve reported above!
I’d be tempted to try them out with the Orange Chromides, and as/when they mature, if they start looking seedy, or else behave abominably, then move them into a more rough and tumble FOWLR system.
Cheers, Neale
<Thank you, BobF>

Re: Damselfish Identification - Neopomacentrus      11/22/19
Bob, Neale,
<Hello Joel,>
Thank you for the additional information and advice. The mention of Apogon was very interesting as well - I'm really only familiar with the more common Pterapogon and Sphaeramia Cardinals and was unaware of any brackish Cardinalfish.
<I know nothing about the estuarine Apogon species, except that they exist.>
The temptation was too great and I purchased one of the Demoiselles, acclimating it to 1.006 over the better part of the evening. It colored back up right away in the tank and was eager to eat so I am optimistic it'll do well.
<Me too; by all accounts they are very hardy, much like other Damsels.
Given virtually all the bread-and-butter Damsels have been kept in high-end brackish conditions for years (i.e., at SG 1.018) during the earlier years of the marine hobby, I imagine the truly euryhaline species to be very adaptable.>
There was mutual interest between the fishes but no hints of aggression thus far. The tank includes multiple pieces of PVC pipe covered in oyster shells, slate caves, and lots of plastic plants so hopefully there will be enough territories for all. I don't typically see Chromides protecting spaces/caves for the most part so it's a fairly mellow tank.
<Cool. Chromides become more aggressive when spawning, but their ecology is interesting, since they mix with schooling Green Chromides as some sort of 'cleaner fish' symbiont. So they're probably 'wired' to be fairly easy going with fish they don't see as an immediate threat.>
As you mention this is an uncommon fish in the trade, would you be interested in periodic updates on health, behavior, and compatibility with some of the "classic" brackish aquarium fish? I'd be happy to provide.
<I'd be most grateful, in fact, to receive such!>
Thank you again for all your time and help,
<Cheers, Neale.>

Re: Damselfish Identification - Neopomacentrus      12/5/19
Good evening,
<Hello Joel,>
Almost two weeks ago I purchased a Freshwater Demoiselle (Neopomacentrus taeniurus) for my 125 gallon brackish tank. I thought I would give you an update on how everybody is doing thus far.
The tank is 125 gallons, currently 77 F, about pH 7.8, and dH 15. The specific gravity is normally kept at 1.006, though I checked today and it's crept up to 1.008. Not a huge deal I imagine, but I'm going to bump it back down next water change.
<Indeed, no big deal. Truly euryhaline brackish water fish, like these, can adapt to anything from fresh to seawater within minutes, in the sense of it not causing them long-term harm. There's some scientific evidence it likely takes them days to properly, fully adapt, but unlike marine or freshwater fish, exposure to salinity changes isn't actually lethal or even stressful, and in the wild they'd have to be able to handle these simply to survive.>
So far the Demoiselle has been in fantastic health. Great color, fins look perfect, and very healthy appetite. I feed a variety of wet and dry foods over the course of the week - he seems to like the New Life Spectrum, Bug Bites fish food, Brine shrimp, and tiny bits of tilapia I offer every few days. He doesn't appear interested in Nori, but otherwise is eating just about anything offered.
<Great. They're zooplankton feeders, so disinterest in Nori isn't altogether surprising. Unlike some reef Damsels, they aren't major algae eaters. That said, if your chap takes algae-based flake food, that'd be a really useful addition to their diet, as it is for most fish.>
As far as behavior, he claimed one of the PVC pipes closest to the filter and heater as a "home base" but doesn't spend a great deal of time there unless accidentally startled. I see him mostly swimming among the Orange Chromides; occasionally (two or three times over the week) I may see a quick dash towards a Chromide of smaller size to make them leave his territory, but so far haven't seen him dash more than a few inches or physically attack another fish. He'll also do this towards the Knight Goby
who similarly enjoys hiding out in pipes. My Scats are all left alone, though it took a few days to realize they don't actually pose a threat.
None of the inhabitants seem to pay him much mind.
<Sounds good. He does seem to have staked his territory, and with a lot of Damsels, any negative behaviours are really circled around that patch. If they're left alone, for the most part they leave others alone.>
All in all, I'm happy with this purchase. I will keep an eye as he grows to to make sure he doesn't get too "punchy".
<I think BobF referred to this genus as one of the more clubbable species, so with any luck, all should be well. Sometimes moving rocks or whatever around to create obvious territorial boundaries is a useful trick.>
Thank you for your time,
<And thanks for sharing. Cheers, Neale.>

Ick Cure     10/12/19
Good Moring,
Can I use ick cure in my tank that has a Columbian catfish in it.
<The API product? I would NOT use Malachite Green on scaleless catfishes...
Instead, a real cure can be effected here by raising temperature, and possibly adding sea salt. Please READ here:
and the linked files above. Bob Fenner>
Ick Cure /Neale       10/12/19

Good Moring,
Can I use ick cure in my tank that has a Columbian catfish in it.
<I can think of absolutely no reason why you would have to. None at all.
Columbian Shark Catfish are brackish to marine catfish, any above SG 1.002, Whitespot/Ick parasites simply won't survive. The free-living stages will be killed immediately, which means, at tropical temperatures, infected Catfish moved into brackish or marine conditions should be completely free of Whitespot/Ick within a week or so. Conversely, if you're keeping the Columbian Sharks in a saltwater system, moving them temporarily into low-end brackish or even hard freshwater should kill off the marine Ick, Cryptocaryon, within a few days as well. Oh, and if you're keeping Columbian Sharks in a plain freshwater tank, then don't. Just don't. Add the salt, and the Whitespot will go! Cheers, Neale.>

Scatophagus Aggression      10/3/19
Good evening,
<Hey Joel>
I have a 125 gallon brackish tank, kept at 77F and 1.006 specific gravity.
The inhabitants are 5 Orange Chromides (ranging from 1.5 to 2.5 inches), 2 Silver Scats (7 inches and 3.5 inches), a Green Scat (2.5 inches) and a Green Spotted Puffer (3 inches). I do understand that GSP in general are not good community tank specimens but over the 4 years I've had this fish, he's been with snails, hermits, Damsels, Mollies, and Blue-Eyes (in various tanks) and has never nipped a single animal. He seems to prefer to keep to himself. He's not the issue in this tank.
My concern today is with my Scats. I've had my big Silver Scat for a few years since it was about an inch long and more recently picked up a second Silver to grow and keep company. Having read on WWM that Scats are best in odd numbers and are fine in mixed species groups, my next purchase was a small Green Scat. The Green Scat, despite being smaller, is very hard on the smaller of the two Silver Scats.
It used to be just some pushing during feeding times but over the past 2 months has grown more into antagonizing.
The small Silver still is out in the open, is eating well and not hiding, though is constantly being chased and I worry it's causing him to be stressed and is probably not helping my skittish big Silver Scat to
My queries are twofold:
1) Do you expect that they will mellow out with age or that it will get worse from here? I'm pretty sure it will get worse since it's already been going that way, but figured I'd ask. I understand I'll likely have to
rehome the Green Scat.
<My experience has been that scats do "mellow" as you state... in time>
2) In your experience, is Scatophagus more aggressive than Selenotoca? If I rehome the Green, I'd need to decide if I want to try and special order another Silver Scat or try again with an (easier to find) Scatophagus specimen. I've never had a single problem over the years with either Selenotoca I've owned, even though two animals isn't a great sample size.
<More an independent issue w/ Scatophagids. Have encountered some that are "mean" of all species. IF you are concerned... (I would) move the green to a plastic floating colander (yeah, like for straining the flying spaghetti monster) for a few days, leaving the lights off... This "time out" often acts to reduce aggression, allow the animals to reorient>
I really appreciate your time and advice.
Thank you,
<Thank you for sharing. Bob Fenner>
Re: Scatophagus Aggression /Neale        10/4/19

<<Will add this/these observations to BobF's comments re: Scatophagus and Selenotoca. Yes, aggression varies with age, older specimens tending to become more lazy and accommodating. But also it's more social jockeying than aggression. If the Scats are different sizes, a definite pecking order will exist. Scats are not the worst by any means, and you will see this with Archers and Monos to an even greater degree. This contrasts with Colombian Shark Catfish which school together amicably with any specimens too big to be viewed as food. Anyway, mixing species can help, and works really well between Monos and Scats, where Scats bludgeon their way through the squabbles Monos have, dissipating aggression while the Monos regroup.
In the absence of Monos, adding extra Silver Scats would probably work, the point being that pecking order aggression is most acute where the dominant fish can easily bully one or two tankmates. In large groups, five or more specimens, this gets harder. On top of that, Scatophagus tend to be much more pushy than Selenotoca, this latter species being really quite gentle and placid most of the time. (Indeed, it's a charming, underrated species with the looks of even the nicest marine species.) Scatophagus are, as you probably know, the "garbage men" of the reef and coastline, seemingly ignored by many/most predators because of their unsavoury habits, and because of that, they seem to "go anywhere, do anything" which gives them their friendly charm as pets, but can also make them a bit thuggish in small to medium sized tanks. Cheers, Neale.>>
Re: Scatophagus Aggression      10/6/19

Bob, Neale,
Thank you so much for your time and advice. I went to the local fish store today and asked them to order another Silver Scat for me. In my experience it normally takes about 4 to 8 weeks to get in the fish I order.
<Not too bad.>
I don't believe my tank (at 125 gallons) can accommodate my current bioload and 3 additional Scats to spread out aggression, at least at adult size.
I'll keep an eye on the current Green Scat during this time and if the behavior gets worse I will trade him in once a new specimen is available.
<Understood. Hopefully with additional Silver Scats, the Green will mellow a bit.>
Thank you again,
<Most welcome. Neale.>

Please help - sick puffer     8/19/19
Dear crew,
Could you please give me some advise on my sick puffer. It is a 3 inch Tetraodon nigroviridis.
<I will, but am referring you to Neale Monks here as he is far more knowledgeable re these Tetraodonts>
It started after he ate some snails from another tank. He (or she) was pinching its tail and started to change colour. See pics
<I do>
I have 3 of them and the other two have no problems and are bright coloured.
<I see this as well>
This is about a week. I first put him in a small tank and treated him with ESHA2000. He didn't take that very well; started to float on its back so I took him out immediately.
After a week (yesterday) I treated him with 'SERA BAKTOPUR DIRECT' for 30 minutes and directly after that with 'EASY LIFE VOOGLE'
Sometimes he's real 'lively 'and swims around but often he's just apathetic lying on the bottom of the tank.
The water is good, other fish don't have any problems. Salinity is about 1.005
What should I do?
<Mmm; were it me, mine, I'd cease treatment/s... this fish may have a bit of "stomach ache" from snail shells... and there might be some value in adding a bit of Epsom Salt, but I'd just wait at this point. The fish doesn't look skinny, diseased nor picked on, and will likely be fine in days>
Kind regards from The Netherlands
<Cheers, Bob Fenner>

Please help - sick puffer /Neale        8/20/19
Dear crew,
Could you please give me some advise on my sick puffer. It is a 3 inch Tetraodon nigroviridis.
It started after he ate some snails from another tank. He (or she) was pinching its tail and started to change colour. See pics I have 3 of them and the other two have no problems and are bright coloured.
This is about a week. I first put him in a small tank and treated him with ESHA2000.
<I'm surprised; my puffers have usually done quite well with this product.>
He didn't take that very well; started to float on its back so I took him out immediately.
<Fair enough.>
After a week (yesterday) I treated him with 'SERA BAKTOPUR DIRECT'
<Another antibacterial medication; reasonably good, if less good than an antibiotic.>
for 30 minutes and directly after that with 'EASY LIFE VOOGLE'
<Not familiar with this.>
Sometimes he's real 'lively' and swims around but often he's just apathetic lying on the bottom of the tank.
The water is good, other fish don't have any problems. Salinity is about 1.005
What should I do?
<One thing is to try increasing the salinity and see if that perks him up.
With any brackish water fish, this is a good first step. It replicates what they experience in the wild, and some simply seem to enjoy it. Another thing is to try increasing aeration. Sometimes extra oxygen helps, and this
in turn suggests the aquarium is perhaps less good than we thought. Many brackish water species prefer high oxygen levels that replicate the tidal or littoral habitats they prefer. Finally, and again a good step with
brackish water fish, is to review water chemistry. Most prefer high alkalinity and a pH well above 7; aiming for 15-20 degrees dH, 10+ degrees KH, and pH 7.5 to 8.2 is ideal.>
Kind regards from The Netherlands
<I will observe that GSPs are not really social, and while some specimens cohabit in pairs or trios, not all will do so. Look out for behaviour that might suggest bullying or at least antagonism. Your fish looks essentially healthy, and I would not be randomly medicating unless you have clear symptoms of a disease. Lethargy and dark colours on GSPs can mean nothing more than social or environmental stress. Review, and act accordingly.
Cheers, Neale.>
Re: please help - sick puffer       8/20/19

Dear Neale, Bob,
I thank you for your answers. They are very helpful to me.
<Most welcome.>
I'll stop any medication and start increasing aeration and the salinity. I will also check the water parameters.
<Very good!>
Thanks again and have a nice day!
<You too.>
Kind regards,
<Cheers, Neale.>

Spawning Figure-8 Puffer (Tetraodon biocellatus)      7/21/19
I apologize if im in the wrong place, but i wanted to ask if you guys had any info on figure 8s besides the common info.
My questions are as follows
1. What conditions are required to breed them.
<The species has been bred only very occasionally in aquaria. It is often stated that reproduction is cichlid-like, with the male protecting the eggs until the fry become free swimming. However, this doesn't agree with the scientific literature, which reports that the species scatters eggs and extends no broodcare at all "Spawning of eight Southeast Asian brackish and freshwater puffers of the genera Tetraodon and Carinotetraodon in captivity"). This report stated the eggs hatched after 5 days, used up
their yolk within 4 days of hatching, and became free swimming on the following day. Pufferfish fry are tiny and difficult to rear, and you will need suitably small live foods.>
2. What are the best methods to sex them.
<Again, unknown. These fish are almost certainly monomorphic, with no visible differences between the males and females. To be fair, you could predict the males would be more aggressive and more likely to defend specific patches of territory, given the breeding behaviour. But that's about it.>
3.what are the best conditions for them to thrive in?
<Low-end brackish conditions seem to be best, at least for aquarium maintenance and breeding. There's no question that the species also occurs in freshwater environments, even more commonly than in brackish water. But it doesn't do as well kept that way. The scientific literature includes at least one report on spawning, and that took place in brackish, not freshwater conditions. While the adults were maintain in quite strongly brackish water (20 ppt) for 'several years', they were moved in higher salinity (30 ppt) for a month, and then across the next month the salinity was decreased in small steps until it reached a lower level (9 ppt). By this time the female had become swollen with eggs. The eggs were maintained at this salinity after the adults were removed, hatching taking place as described above. The fry were initially fed brackish water Brachionus, and after 35 days, graduated onto Artemia nauplii. After 60 days they were moved onto the usual frozen foods such as krill, minced clams, etc.>
4. If i were to have a large group of them would that decrease aggression and allow them to shoal or school, boost the odds of them breeding? and what would be a good group size if so?
<Realistically, yes, you'd want a group, and you'd want to keep as many as practical. I'd suggest no fewer than 6.>
5. If you have good resources and info on figure 8s id really appreciate it.
<The paper described above is probably the only truly authoritative article on spawning these puffers. It is available via ResearchGate, for example.>
6. Thank you
<Most welcome. Neale.>

55 gallon FOWLR tank stocking    7/2/19
Good evening,
<Am here now Joel; howsit?>
I am new to saltwater tank keeping but about 6 weeks ago upgraded my 29 gallon high end brackish (1.015) tank to a 55 gallon FOWLR tank. Mostly, I wanted to provide tankmates for my 3.5" Green Spotted Pufferfish (Dichotomyctere nigroviridis) who I've had for about 4 years, waiting until he exceeded 3 inches to start transitioning to saltwater per Neale's advice. I tested the waters - pardon the pun - with Mollies both in the 29 and the 55 and have found my puffer to be very mild, not biting or chasing any other fish at all during the time I've had him. He's even ignored the hermit crab hitchhikers that arrived on some live rock, who are still  happy and healthy to this day. Understood that he may eventually change his mind on the crustaceans, but for now their inclusion is nice.
Currently, the tank sits at 1.023, pH 8.2, temperature 77F with about 40 pounds of live rock and 2.5 to 3 inches of aragonite sand substrate. Given my puffer's relatively mild nature, but understanding their potential to be aggressive, I stocked fish that should in theory be able to cohabitate.
The stocking is currently:
1 Green Spotted Puffer
3 Mollies - 1 male, 2 females (Poecilia spp)
3 Yellow Tailed Blue Damsels (Chrysiptera parasema)
2 Electric Blue Hermit Crabs (Calcinus elegans)
I originally selected the C. parasema due to WWM due to the facts that they are at the low end of the aggression spectrum, that they are suitable for this size tank, and that I live in a small town that really only gets Chromis, Clownfish, and "assorted Damsels". I would have gone for C. talboti otherwise. I had 5 of the C. parasema, but two of them backed up the other 3 Damsels and all 3 Mollies into a corner.... not unexpected, but frustrating. I removed all the rock, caught the 2 offenders, and returned to the store. The third biggest is starting to be pushy so I'm keeping an eye on it and considering whether the last three should be returned to the store.
<I see>
In this case, I am at a loss for how to stock this tank. I've read enough of the articles to know that some of the WWM believe Chromis viridis to be a questionable choice in a 55 gallon, but would they be a better choice than trying more Chrysiptera?
<Chrysiptera genus damsels would be better temperament wise>
I'm trying to go for a peaceful tank atmosphere and would prioritize peace over fish that are more  "classically beautiful."
Other than Damsels, I am not sure which families or genera to investigate.
I am avoiding fish that are sedentary or have long fins (like Firefish) to avoid puffer temptation but am looking for any nudge in the right  direction to do research. I would appreciate any suggestions you could offer.
Thank you for your time,
<Well; you'll have to raise the specific gravity of the water for most full-strength seawater species... there are (still) many choices. I'd have you consider other brackish to marine groups for now. Perhaps Scats, Toxotids... Let's have you peruse here: http://www.wetwebmedia.com/brackishsubwebindex/brlvstselfaqs.htm
Bob Fenner>
Re: 55 gallon FOWLR tank stocking       7/3/19

Thank you as always for the quick response. I found two of the Chrysiptera
dead today, not sure if from aggression or illness, but in any case my stocking plans are on hold for a few weeks while I keep an eye on it and  do some investigating.
Scatophagidae is my favorite family of aquarium fishes; my 125 gallon brackish tank has two Selenotoca and one Scatophagus in it and they are wonderful pets. I thought about Toxotes spp. but those that can tolerate full saltwater got a little bigger than I really wanted and I feared they would eat my (mostly smaller) current fish.
<They rarely eat all but the smallest fishes>
I will look into some brackish fishes as well; the Blue-Eye Pseudomugil cyanodorsalis may be obtainable here, potentially Butterfly Gobies (Neovespicula depressifrons) as well. Would love Diamond Killifish but doubt I'll ever come across them. In any case, I'll speak to the stores and see what they can order.
Thank you again for your time,
<Do please keep us informed re your thoughts, activity here. BobF>
Re: 55 gallon FOWLR tank stocking        7/14/19

Following up on our previous conversation. I was able to acquire 4 Pacific Blue Eyes (Pseudomugil signifer)
<A fave species; I raise them here.>
which I am currently in the middle of drip
acclimating. They seem to be doing well at this current time, hoping they get along with the Mollies and Yellow Tail Blue Damsel (Chrysiptera parasema).
<Hope the Damsels are small, the Blue Eyes big>
Besides that, I am currently trying some spare bits of Aegagropila algae in the tank to see if it takes off. So far, after a week it's still perfectly green, so that is a pleasant sign.
The store I went to did in fact have an available Talbot's Damsel (Chrysiptera talboti), at a larger size than my current Yellow Tail resident - 2 inches compared to 1.5. Given my Yellow Tail Damsel fought
constantly with the other Yellow Tails, is it likely it would also fight in a 55 with a Talbot's?
<Might; though most all Chrysiptera get along as individuals, between species>
Thank you as always for your advice,
<Glad to share. Bob Fenner>

Brackish puffers; sel., sys.        4/5/19
Hi Neale,
I am setting up a brackish water tank, currently it is 1.006 and I am slowly increasing it to 1.010 (the reason being that it is a mature freshwater tank and I don't want to kill all of the good freshwater bacteria by increasing the salt content all the way to 1.010 on day one).
<Understood, but for most brackish species, 1.005 would be just fine.>
I am wondering, which of the 'marine' puffers will do OK in a brackish around 1.010?
<Interesting question! The obvious pick is Chelonodon patoca, which is a marine species, but routinely inhabits estuaries and rivers. It seems completely indifferent to salinity, and should do well in a half-strength system indefinitely.>
I understand dog faced puffers are OK?
<Arothron hispidus will remain healthy for a long time in half-strength seawater. Whether indefinitely is hard to say. The species enters estuaries, and the juveniles live in them. But adults are really coastal marine, even reef fish. Not really river dwellers. So fun inmates for a brackish tank while young, but I'd probably move adults to marine tanks.
<<Yes; this species lives in full strength seawater as adults>>
Can a porcupine be kept in 1.010? - I am really keen on this one.
<Never seen these in brackish tanks, nor heard of them being recorded in such conditions for extended periods. Adults are open water marine fish, and while juveniles surely do inhabit estuaries, it's probably a temporary thing. I dare say you could experiment, and if they showed signs of distress, returned them to full marine conditions. But not convinced it'd be worth the effort.>
If so can these two be kept together?
<Generally these puffers are solitary and squabble in anything other than public aquaria.>
is there any others you can recommend?
<See above re: Chelonodon, a lovely, and actually quite sociable, species.
It used to be very rare, but gets exported out of India fairly regularly.
There's a "Golden" subspecies or related species available as well, and it's even nicer. If you have a really big tank, Colomesus psittacus is another marine species that inhabits estuaries more or less permanently, but it's very rare in the trade. You'd need good contacts in the South American trade to get it, and unfortunately the more casual importers are likely to confuse it with the strictly freshwater Amazon Puffer, Colomesus asellus.>
<Welcome. Neale.>
Re: Brackish puffers (BobF, some input please)<<Ok>>       4/5/19

Thanks Neale,
<Hello again!>
With the Arothron hispidus, could they be introduced whilst the salinity is still at 1.006 or best to wait until 1.010?
<When I bought my two specimens, they were sold as freshwater fish!
Juveniles (say, 1-3 inches long) would be just fine in a low-end brackish system at SG 1.006, provided the water was reasonably hard, alkaline and well oxygenated. Observe their behaviour, and if they are lively and feeding well, act accordingly.>
Do you have any suggestions where I can locate a Chelonodon patoca? None currently for sale at any of the regulars...wharf aquatics..wildwoods etc.
<Wildwoods is where I've seen them at least twice. Keith Lambert at Wildwoods is pretty good at getting stuff if it's out there. Aquarium Glaser has them on their (wholesale) stock lists so finding a store that works with them could be a start.
Again, speaking with the likes of Keith is going to be helpful.>
<Cheers, Neale.>
<<AquariumFish.Net lists them for sale:
Otherwise I'd contact the folks at LiveAquaria.com if your LFS can't/won't special order for you from their wholesale suppliers. Bob Fenner>>
Re: Brackish puffers (BobF, some input please)<<>>       4/5/19

Sorry, one last question,
Could either of these species be kept with a green spot or figure 8 puffer in a big enough tank?
<Juvenile Arothron hispidus are quite tolerant, but may be snappy if they feel cramped. Adults are distinctly territorial, but otherwise not too aggressive. By all accounts Chelonodon patoca is very easy going, and
should tolerate dissimilar species just as well as they tolerate one another.>
<<I would NOT mix the larger Tetraodontids with much smaller species; too likely to be harassed and all food outcompeted for. BobF>>
<I'm going to direct you to some writings of mine on marine puffers that tolerate brackish, here:
Some day I should import all of this into WWM, but for now, hope it's
useful. Cheers, Neale.> 
Re: Brackish puffers     4/8/19

Hi Neale
Good news!
My LFS has found Chelonodon patoca on an import list with 17 available at £10.99 each. Great result.
<Indeed. And a very decent price, too. When they were in at Wildwoods they were going for something around the £50 mark, I think.>
They’re going in a 5 foot by 2 foot that I’m going to slowly make brackish.
At that sort of size tank - how many should I go for?
<Tricky. As juveniles, either a singleton or at least three. While a fin-nipper according to some, it's apparently pretty peaceful towards its own kind given adequate space and hiding places (they like to dig into the sand). But twos can sometimes work out poorly in any species, so adding at least a third ensures bullying is spread out a bit. Adults can get pretty large, though 30 cm/12 inch specimens seem exceptional. Nonetheless, you should be expecting something around 20-30 cm/8-12 inches when fully grown, and even in your very large aquarium you might struggle to house three adults, let alone more. Rehoming semi-adult specimens of these very rarely seen pufferfish shouldn't be a problem though, especially given their utility in marine aquaria. So I'd be tempted to get three and grow them on, but with the proviso that in 3-4 years I might need either a bigger tank or to rehome two of them.>
<Cheers, Neale.>

Green spotted puffer      3/30/19
I have had my green spotted puffer for 2 years now. I have him in a 5.5gallon tank, ( I know he needs a 10 gallon tank)
<And the rest! More like 20+ gallons -- adult GSPs are, what, 12-15 cm/5-6 inches long.>
but he has been fine, until now.
<The "until now" is the key part of the sentence, really. Two years isn't bad at all, so obviously you're doing some things right. But some things evidently aren't right.>
His belly goes from white to black, and he is staying at the top of the tank at a vertical angle.
<Signs of stress; when GSPs become inactive, dark in colour, and disinterested in food, then something is very wrong.>
Or stays with his beak pushed into a corner of the tank. But the last 3 days he has not been to the bottom at all and is being tossed around or flipping around like an acrobat & I know that's not normal.
<This is very bad.>
I just did a 60 percent water change.
<What sort of water chemistry values are we talking about here? To recap, a GSP this age really needs strongly brackish water; I'd be aiming for SG 1.005-1.010. Needless to say ammonia and nitrite must be zero, but nitrate should also be as low as practical; below 20 mg/l is ideal, and certainly no more than 40 mg/l.>
Filter is only a couple weeks old.
<I don't understand this exactly. Do you mean you changed the old filter for a new one? If so, then the new filter could be cycling and ammonia and nitrite above zero. That could easily account for the problem. If you mean the tank had no filter at all until two weeks ago, I'm surprised this puffer survived until now.>
I know not to change everything all at once. Is he dying? I think I'll die if he does.
<My first step would be to check the salinity. Strongly brackish water will help. If you're dosing salt in "teaspoon per gallon" amounts then you're not doing it right. You really need substantial amounts of marine salt mix. For SG 1.005, at 25 C you'd be dosing the salt at 9 grams per litre (1.2 oz per US gallon) which is quite a bit -- 9 grams is about 1.5 teaspoons of typical salt mix. I'm also going to ask you to check the ammonia and/or nitrite levels. If they're not zero, then that's a major problem that needs
urgent attention. I'm finally going to have you do some reading, here:
Hope this helps, Neale.>

More Spaghetti eel observation      3/10/19
Hello Neale, Marco and all of you good people at WetWebMedia,
<Hello Ben,>
Here are more observations of spaghetti eels behavior.
<Very cool. Looks like a great brackish water community tank you've got there.>
I traded the larger eel with a medium sized one. Now they both seems to be same species. I also look forward to receive a Lamnostoma kampeni eel maybe within a few months.
<Now that's something you don't see in the trade very often!>
My spaghetti eels now spend much more time under the sand. Often for days.
They only come out when hungry. But once they feel hungry, they will come out and will take chunks of shrimps bigger than their mouths.
<Cool. Do be careful with shrimp, prawn and mussel meat though. Contains a lot of thiaminase. Implicated in long-term vitamin deficiency problems in carnivorous animals. Use as maybe one-third or less of the food offered. Use white fish fillet, cockles, squid and other thiaminase-free foods for
the majority of their diet.>
They also make the interesting body knots like morays when eating. And they also capable of snagging food 'from above' like a snake eel.
My procurer recommend me to put my moringuas in full FW, or if I really have to have brackish (for my GSP and brackish tilapia), he recommend low-end brackish. Higher brackish would make uncomfortable both Moringua and Lamnostoma, he said.
<Certainly worth experimenting. With these eels what you tend to see is a hunger strike if the salinity is wrong, weeks or months before the fish dies. So if the fish continue to eat well in low-end brackish or freshwater conditions, and there's no evidence of skin infections, then they could well be fine. Realistically, they likely move in and out of estuarine conditions, and there might be no "perfect" salinity, and instead offering a few months in salty water, then a few months in fresh, would actually be best.>
Well, that's my current observation. I will report more when I received the Lamnostoma. Thank you and have a wonderful weekend!
Best Regards, Ben
<Thanks so much for writing. Lovely videos! Neale.>
Re: More Spaghetti eel observation     3/12/19

Hello Neale and all you splendid people in WetWebMedia,
Thank you for your quick reply! And thank you for complimenting my aquarium. Indeed it is a nice brackish aquarium community, low brackish at 1.005sg.
<Sounds great!>
The happiest inhabitants of my aquarium are the huge brackish tilapia (never get to know its Latin/scientific name. It is caught in the estuarium together with the mollies. I wonder what kind of tilapia is that?) and those two lovely Tetraodon nigroviridis. Interestingly, all those scary stories about pufferfish being aggressive barbarians does not apply on my tank, the puffers doesn't harm anyone, not even the smallest of mollies. In fact the tilapia is much more aggressive and greedy.
<Well, Sarotherodon melanotheron is the 'true' brackish water Tilapia, but most of the farmed species will handle brackish, even marine, conditions, including Oreochromis mossambicus, Oreochromis niloticus, Sarotherodon galilaeus and Tilapia rendalli.>
My puffers loves to bite on empty clamshells & sea snail shells, maybe they try to eat the worms and/or pieces of shrimps which sticks on the shells. Or do they like to munch on those to get more calcium?
<Might be either explanation, or both.>
As for shrimps, thank you for your advice, I will try to give my eels more varied diets as per your advice. Fish fillets usually does not survive human predation in my refrigerator ;) . So I will stock on squids for the eels. BTW what are cockles?
<Cerastoderma edule. But other burrowing marine clams probably just as good.>
Spaghetti eels are nice to have but I now understand why they are not popular as pets around here. Their lifecycle seems to consist of hiding under the sand, only came out for taking bits of food, then went back hiding for days. So most of the times, a keeper of spaghetti eels would feels like having no eels at all. They also said that larger morays would see much smaller eels as worms. So maybe I will have to rehouse my Whitecheek to accommodate more smaller eels, considering I will have Lamnostoma coming.
I really hope I could upgrade to a bigger aquarium someday. Right now I usually give away my eels once they grown too big for the aquarium.
Well, thank you very much for your kind comments, and I will keep you posted!
Best Regards, Ben
<And to you, good luck! Neale.>

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