MadSci Network: Zoology |
Hi:
I assume you're referring to Melanostomias valdiviae, or a very similar member of the (generally very creepy looking!) family Stomiidae (both links are from FishBase, a very handy online database about known fish species). Like you wrote, most Stomiids (pronounced "Stow-mee-id" by the way) live in the deep ocean, and not very much is known about their biology. They are solitary and not particularly abundant, so they can be quite difficult to catch. Really the only way to catch them is to trawl for them with nets, and as a consequence they're usually not in very good shape when they arrive at the surface.
For the most part fish have external fertilization, that is to say that
gametes (eggs and sperm) are released by females and males into the water, and
fertilization occurs outside of the body. Most fish do not exercise any care of
their young, who are basically on their own from the egg stage onward
(with a very heavy mortality as a result of that). There are a few exceptions
to that - some fish are known as livebearing,
and actually retain their eggs internally until they hatch (sort of like giving
birth). Some of the more common aquarium fish like swordtails and guppies are
livebearers, as are some Scorpaenids
(Rockfishes).
Some other families of fish take care of their larvae in nests - Centrarchids
(bass and sunfishes) and Cichlids are
known for this for instance. Often, the male is responsible for guarding the
larvae, and they may forgo feeding for weeks or months to do this (they also
sometimes mouthbrood - keep the larvae safe within their mouth - which is also
not conducive to eating!). Most fish that take care of their young are what we
call demersal
- they live their lives at or near the bottom. Dragonfish, on the other hand,
are pelagic.
So, my educated guess would be that they do not take care of their offspring
in any way. Looking around in FishBase, I did find one species within the
family Stomiidae, Idiacanthus antrostomus which has a reference as
having pelagic larvae (there may be others if you look through other species in
the
family), which you could call weak evidence for other species within the family.
Hope that helps!
Rob Campbell, MAD Scientist
Try the links in the MadSci Library for more information on Zoology.