Danionella dracula

One of the evolutionary peculiarities of my favorite lab animal, the zebrafish, and of cypriniform fishes in general, is that they lack teeth. They lost them over 50 million years ago, and don't even form a dental lamina in development. So this photo of a cypriniform, Danionella dracula, gave me a bit of a start beyond just the nice fangs and the ghoulish name.
The story doesn't give much detail, but I'm going to have to look into this. Those are not true teeth, but spiny outgrowths of bone directly from the jaws.

Ghostshark (hydrolagus melanophasma)

A new ghostshark species has been identified off the coast of Southern California, and

it’s darker and weirder than any shark we know.

The purplish black ancient relative of the modern shark comes packed with a suite of odd features that give its taxonomical family the name chimaera, after the mythical beast made from the parts of many animals.

“It’s a big weird looking freaky thing,” said ichthyologist Doug Long of the California Academy of Sciences. “They have some shark characteristics and they have some that are very non-shark.”

Perhaps the most intriguing feature of the newly described species, Hydrolagus melanophasma, is a presumed sexual organ that extends from its forehead called a tentaculum.

“They have this club on the top of their head with spikes. People think it’s used for mating,” Long said. “It’s like a little mace with little spikes and hooks and it fits into their forehead. It’s jointed and it comes out. We’re not sure if it is used to stimulate the female or hold the female closer.”

Indonesia's psychedelic fish named a new species

JAKARTA, Indonesia -- A funky, psychedelic fish that bounces on the ocean floor like a rubber ball has been classified as a new species, a scientific journal reported. The frogfish - which has a swirl of tan and peach zebra stripes that extend from its aqua eyes to its tail - was initially discovered by scuba diving instructors working for a tour operator a year ago in shallow waters off Ambon island in eastern Indonesia.
The operator contacted Ted Pietsch, lead author of a paper published in this month's edition of Copeia, the journal of the American Society of Ichthyologists and Herpetologists, who submitted DNA work identifying it as a new species.
The fish - which the University of Washington professor has named "psychedelica" - is a member of the antennariid genus, Histiophryne, and like other frogfish, has fins on both sides of its body that have evolved to be leg-like.
But it has several behavioral traits not previously known to the others, Pietsch wrote.
Each time the fish strike the seabed, for instance, they push off with their fins and expel water from tiny gill openings to jet themselves forward. That, and an off-centered tail, causes them to bounce around in a bizarre, chaotic manner.