Fish o' the Day - lancetfish

Now, for something completely different. The lancetfish are two species in the genus Alepisaurus, the longnose lancetfish A. ferox and the shortnose lancetfish A. brevirostris. They are the only living members of the family Alepisauridae. I wasn't familiar with the animals until I was having dinner one night at a restaurant in Pensacola, and they had one on the wall. They are remarkable looking things, sometimes exceeding 2 meters in length, with long fangs and a broad sail-like dorsal on an elongate body.

They are (as far as we know) among the largest of the wholly mesopelagic fishes, where they are voracious predators. In fact, quite a few midwater fish species are know only from their occurrence in lancetfish stomachs. Their somewhat flaccid musculature suggests that they are likely ambush predators, hanging in the water until suitable prey comes within striking distance. We know them best as bycatch in tuna fisheries, although an occasional specimen washes up on the beach.