Ask the WWM Crew
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Where do the various fishes, invertebrates, algae, live rock and sand used in the marine aquarium hobby come from? The vast majority, well in advance of 99% are wild-collected, harvested from wild stocks from the worlds ocean shallows. Captive bred and reared and cultured livestock increase every year in the species and quality available, but they still make up a pittance compared with what's taken from the seas.
The methods and techniques of gathering are diverse and important to end-users, aka hobbyists, as the degree of roughness and consequent trauma in capture, retrieval and holding at the production end of the trade to a large degree figure in subsequent vitality. No matter what care rendered and high degree of optimized and stable environment utilized, overly stressed specimens easily perish due to "anomalous" causes if improperly collected and handled.
Here is a rundown of the principal ways captive marine livestock is procured, with examples and graphics illustrating the chief types of livestock produced therein.
Tank-Bred & Raised:
This is the best category of livestock source for its high survivability and adaptability of specimens, let alone ethical considerations of reduced natural habitat destruction and diminishment of wild stocks. Some of us are old-in-the-trade enough to remember how frail wild discus and freshwater angels used to be before the unnatural selection of captive bred generations. Multiple lines of captive breeding render much tougher, better aquarium-suited livestock, both fresh and marine.
Some celebrated examples of cultured saltwater fish species that are tank-bred and raised are:
Cultured Non-fishes are also produced in captivity in good numbers. Success stories include a few of the shrimps used in aquariums. Here the boxer shrimp called the Banded-Coral, Stenopus hispidus, Lysmata amboinensis (De Man 1888), the Indo-Pacific White-Striped Cleaner Shrimp or Ambon Shrimp. Even Lysmata debelius Bruce 1983, the Scarlet Cleaner Shrimp, or Blood Shrimp has been commercially produced by Tropic Marine Centre in the U.K.
Some of these organisms are induced to spawn through environmental manipulation, others through hormonal inducements, still others non-sexually be vegetative growth and manual splitting. They have all proven to be heartier, more disease-resistant, faster growing, accepting of captive conditions than wild stock equivalents. My advice, buy them when/where you can.
Barrier (and Hand) Net Caught:
This is the most common method of saltwater fish-livestock capture, probably accounting for 85-90% of the total. Though there are variations/modifications on the theme (height, mesh size and type for different intended species and settings…), basically a fence or barrier net is a transparent rectangle of netting with a lead line at the bottom and float line at its top. This is carefully deployed after surveying a prospective bottom, generally first driving off the intended catch from the territory ("Hey, they will come back"). The barrier net is typically set with one or more pockets in a "U" or "W" shape with a rock or tie-back (bungee or rubber hook) to make a concave indentation (pocket) in which the catch is driven by hands or "chaser poles". Specimens are hand-netted off the fence net, and transferred to collecting baskets for holding and decompression.
Many fish groups are harvested utilizing this technique, including most of the Tangs (Clown Surgeon, Acanthurus lineatus, Atlantic blue tangs, A. coeruleus, the Red Sea endemic, A. sohal, the Combtooth Tangs, genus Ctenochaetus, here C. strigosus, the Kole or Yellow-Eye Tang, the Pacific Yellow-Tail Blue Tang, Paracanthurus hepatus, and all members of the Sailfin Tang genus Zebrasoma, here the ever-popular yellow Z. flavescens, off of Kona, Hawai'i in shallow water.
Butterflyfishes (B/Fs) are most frequently caught with Barrier/Fence net technology, including the Threadfin, Chaetodon auriga, Saddleback, C. ephippium, Raccoon, C. lunula, Longnose B/Fs of the genus Forcipiger, the Pyramid B/Fs, genus Hemitaurichthys, and Bannerfish B/Fs, genus Heniochus.
Most Wrasses are collected in such nets of smaller mesh and height. Some examples are the Hogfishes, genus Bodianus, here B. anthioides, Coris Wrasses, Bird Wrasses, genus Gomphosus, among many, many others),
Undesirables: A note regarding varieties you don't want in your fence net, Triggerfishes, family Balistidae, like bullets such as Xanthichthys mento; and Parrotfishes, family Scaridae, here a male Stoplight Parrot, Sparisoma viride, and Sharks, here a "baby" Reef Blacktip, Carcharhinus melanopterus, are real nightmares, chewing a hole that the rest of your catch swims through, otherwise destroying your net and workday. All three have swum through my collecting nets...
Hand-Netting "on the Fly", etc.:
Think you're quick with a net? Got good eye/hand coordination? Some fishes, and many non-fishes are scooped up mano-a-mano, with naught but cunning, speed, and dexterity… others call for special "tools" in concert with a hand net.
Basslets, like the Royal Gramma (Gramma loreto) are hand-scared into a net coming from the opposite direction, as are some Eels (e.g. the Snowflake Moray, Echidna nebulosa), many Puffers (the Cowfish, Lactoria, a male Blue-Boxfish, Ostracion meleagris, an oh-so-cute Burrfish, Diodon, Dogface Puffer, Arothron nigropunctatus, and the small Sharp-Nosed Puffers or Tobies of the genus Canthigaster). Ditto for wild Clown Anemonefishes (the Red Sea Amphiprion bicinctus here with their host anemone) and Hawkfishes (family Cirrhitidae, here Forster's, Paracirrhites forsteri); they can be literally pushed into a handnet.
Requiring a tool to "block" their rear escape are such fishes as the Dartfishes, family Microdesmidae (here the Scissortail Dartfish, Ptereleotris evides) which darts like its name, lightning fast unless you cut-off access to its coral lair. A clear acrylic panel on a likewise transparent rod does the trick. Burrowing types like the Jawfishes (family Opistognathidae, here the Pearly Jawfish, Opistognathus aurifrons) can be induced to leave their burrows by shaking a shovel-like device in advance of their holes. Alternatively, they and some sand-diving wrasses (e.g. Halichoeres, here one of the three species called Christmas Wrasses, Halichoeres ornatissimus) can be scooped and shaken free of the substrate ala so much cat litter, if you have a strong edged, wide-enough mesh net.
Lastly I'll mention literally running down some fishes like the pelagic Black-Tip Reef Shark (Carcharhinus melanopterus) on open reef flats (here in the Maldives in a foot of water) during propitious tides. Wear shoes and watch your fingers! Juvenile Bat, or better Spadefishes, family Ephippidae, will often "lie-down" when pursued in the shallows hoping their similar appearance to mangrove leaf litter will disguise them (here the Orbic or Round Bat/Spadefish, Platax orbicularis as a leafy youngster and adult)
Slurp Guns; Fun But Not Very Efficient:
In The Darkness of the Night:
If you're not afraid of the dark or the Tiger Shark (Galeocardo cuvier) behind you, a bunch of fishes and money can be had by "picking them up" while they "rest" on the ocean floor. Most everything can be gotten this way. Notable examples include the soft bodied Achilles tang (Acanthurus achilles) which is easily damaged while thrashing around in a barrier net during daytime, and the otherwise dangerous-when-large Naso Tangs (here Naso lituratus' all and working end), Parrotfishes, family Scaridae, (here a sleepy Scarus ghobban, in its mucus cocoon, and a similarly dozing Rabbitfishes, family Siganidae (here Siganus spinus). Though not great pet-fish, even expensive Morays, family Muraenidae like the Dragon (Enchelychore pardalis) can be picked up (in their case with a net) relatively easily while they're out and about foraging at night.
Obviously, it is important to know how to carefully pick up such specimens.
Even lazier than night scuba-hand fishing is the use of static traps. Rabbitfishes family Siganidae, Eels (here the Laced Moray, Gymnothorax favagineus) and more find their way into their fyke funnels (a fish trap in place, Cebu, Philippines), baited or no.
Hook & Line:
Some toothy, largish, just plain too stealthy types are caught on baited barb-less hooks. I've fished underwater for Harlequin Tuskfish (Choerodon fasciata) in Australia, and around the world for Basses (here a Blue Spot, Cephalopholis argus) and their relatives, and above water for such fishes as those seawater piranha, the Triggerfishes (here the Queen, Balistes vetula, holding court in the Caribbean), and Sharks, small (here the Banded Cat Shark, Chiloscyllium punctatum), and not (a Nurse, Ginglymostoma cirrhatum, and Carpet shark, the Spotted Wobbegong, Orectolobus maculatus, family Orectolobidae).
Are defined by their activity; temporary, specific (to the central nervous system), and reversible. Quinaldine and MS222 are used in some parts of the world to narcotize expensive specimens (two western Atlantic Angels often involved, the Rock Beauty, Holacanthus tricolor, and the Queen, H. ciliaris, and I wish they weren't. The same species coming from farther away from Florida often "do better" (i.e. eat and live) then those that have been juiced by some collectors more northerly. There are folks that would/will argue that "relaxing" especially larger individuals is actually beneficial; it cuts down on trauma and physical thrashing. I don't agree. There is a definite differential mortality between anesthetized and non-anesthetic collected specimens. The latter often have more torn finnage, but this repairs over time. The former too commonly fail to thrive for unknown reasons.
Alas, there are still places (parts of the Philippines and Indonesia) where cyanides, bleach, plant extracts and more are utilized to "goose" specimens out of coral and rock. These toxins are not anesthetics. Their effects are general, often irreversible, and permanent (mortuus est). They are biocides, killers of life by etymology. Know which species are frequently doomed by poisoning from these sources and how to identify them (e.g. perhaps the most notorious most likely to be cyanided Angelfish Subgenus Euxiphipops, the Majestic Angel, Pomacanthus E. navarchus, Six-Banded, P.E. sexstriatus, and Blue-Face, P.E. xanthometopon). Is the specimen alert? Interested in its environment? Responding to your presence? "Normally" colored?
Better still, learn to "play the game" with these and other suspect wildlife, put a deposit down, leave the prospective buy at the dealers for two weeks, and be assured it's feeding. By doing so you will avoid virtually all poisoned livestock.
Collecting Sessile Invertebrates... Many species, groups can be simply "picked up" if not attached... Some must be kept separated lest they poke, toxify others in the "catch"... for attached species, often simple hand tools are utilized to break a piece/section, or crack the substrate around the base of the animal/colony.
To Do: Add the old Tim pix from FJ... From... home machines or... desktop in HI?
Several methods are employed in gathering or producing livestock for the ornamental marine aquarium trade. Each strategy has its target prey, and prospective catch per unit effort. For the purposes of judging up and down the line of supply, it is useful to realize just how ones aquatic charges were captured, held and transported. All come to bear on the likelihood of continued success in maintaining captive aquatics.
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