RE: NANFA-- FWD: Protect the Atlantic spiny dogfish!

Bruce Stallsmith (fundulus_at_hotmail.com)
Sun, 12 Mar 2000 17:45:13 EST

I plead guilty to using spiny dogfish in my classes at the University of
Alabama in Huntsville. We're now in the middle of a three-week animal
phylogeny lab sequence, using six species of animals: dogfish, white rats,
frogs, squid, crayfish and earthworms. The way I set it up is that each lab
section, of 10-25 students, dissects one or two of each of the first four
animals, and maybe 4 or 5 each of crayfish and earthworms. The point is to
compare how the different animals make their living in different
environments, where each one has to respire, eat, poop, reproduce,
osmoregulate, etc. Due to ordering snafus with Wards Biological Supply we
used one pregnant shark in each lab section, and no others; so I used a
total of 10 this semester (for 140 students).

I admit to some confusion on the scarcity of dogfish off the New England
coast. Since the original bottom fish such as cod, haddock and fluke have
been severely overfished, large number of dogfish filled their largely open
ecological niche. Whether fishing from a boat or surfcasting, if you were
fishing for striped bass or bluefish with live bait you were very likely to
catch dogfish and nothing but dogfish (good fight, but not especially edible
by modern American standards). My impression was that dogfish has two
commercial uses: there is a demand for dogfish in Chinese cuisine, and
sometimes dogfish is used for British fish & chips, or is punched out in
little circles as fake scallops. It's been four or five years since I paid
much attention to dogfish demand; where is the demand for dogfish coming
from? I suppose I should check out the previously mentioned web page. But
commercial fishermen I knew in New Bedford, MA, hated dogfish years ago
because they'd catch so many of them in their nets, and wind up dumping them
back. Maybe times change...

--Bruce Stallsmith
in sunny Huntsville, AL

>Spiny dogfish (Squalus acanthias) were "standards" for general biology and
>anatomy courses. I dissected two in high school (Marine Biology and
>[mostly-]Human Anatomy), and at least one in college (Comparative
>Vertebrate
>Anatomy). I assume that specimens are still used in courses like these.
>
>It would be interesting to know how many dogfish are used for dissection
>relative to their other uses. I assume that the percentage is low, but the
>numbers collected may be fairly high as specimens are still reasonably
>inexpensive. One biological supply company offers 27" + specimens for
>$6.50-$7.00 each, $12.70 if they are injected, $9.30-$10.30 if they are
>pregnant. Dogfish pups are $1.05-$1.80. A 14" gar, by comparison, is
>$9.25
>and would provide an interesting example for comparison with modern bony
>fishes, amphibians, etc. Of course, the tools in most student dissecting
>kits, and the students themselves, may not be up to the challenge presented
>by ganoid armor.
>
>My vertebrate anatomy prof told our class that historically tuataras were
>readily available for dissections. Biologists, who should have been
>sensitive to the danger of over-collecting long-lived, slow-to-mature
>animals, apparently used them anyway, despite their rarity and limited
>distribution.

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