cross-posted from: hexbear.net/post/9915749

A photo of a specimen of the Apseudes ranma species, a type of crustacean

This is a view of the top/back side of the species. The head is on the left-hand side.

This is the first species in Malacostraca (largest class of crustaceans) known to be capable of self-fertilization, i.e. they’re simultaneous hermaphrodites. So, the guy who confirmed A. ranma as a distinct species sought permission from Rumiko Takahashi herself to name the species after ranmao because Ranma has that whole gender thing going on. It is a new species in Apseudes because it has more spines on the second to fourth walking legs than other Apseudes species: this is an absolutely tiny species, and that’s the level of “spot the difference” you have to do in these sorts of cases. Like you go to the Wikipedia article for Apseudidae, and you might see the picture and think that’s a picture of A. ranma, but no, that’s A. leach, different species! same-picture

Apropos their legs, they have these structures on their legs that are theorized to be used for communication, that rubbing them could produce a sound, except they’re so small that it’s difficult to know if it makes a sound at all. Dr. KAKUI Keiichi first found the species in 2009 in the sand at Port of Nagoya Public Aquarium; the research confirming its self-fertilization was published in 2013. MATSUSHIMA Yoshinobu was assigned to Dr. Kakui’s lab in 2022, and made confirming A. ranma’s status as a distinct species the subject of his bachelor’s thesis. In 2024, that was published. This Hokudai article is from 2025.

So yeah, it can take a long time to confirm a new species, huh! It’s important work. I always end up thinking about this old picture when I read about new species being identified:

Screencaps of corresponding scenes in Tokyo Mew Mew and its reboot Tokyo Mew Mew New with the caption “Probably the most depressing example of a modernization change in Tokyo Mew Mew New”. The first screencap has subtitles reading, “According to the brochure, more than 2500 species face extinction.” The second screencap has subtitles reading, “there are over 15,000 species on our planet in danger of going extinct.”

Neither of the numbers in those screencaps are anywhere close to the actual number of species threatened with extinction (1,000,000 according to the UN in 2019), but in any case the reason why the number of species threatened with extinction keeps ballooning is because of a combination of (1) anthropogenic climate change, which can and must be stopped by overthrowing the cancer on our planet known as capitalism, is leaving increasingly more species vulnerable to extinction; (2) we know about more species than we did before, and the species we’re only just learning about now tend to be the ones most vulnerable to climate change, right?

As for species being named after pop culture: part of it is scientists being big ol’ nerds, part of it is because “I named a species after a manga character” is a guaranteed headline that means more publicity for these sorts of overlooked species and the work that goes into researching them. It’s a good way to get the general public engaged.

christmas-crab-legs You should watch SPARKLE ON RAVEN: The Life of DrillGirl; it is a very good show. {Cēterum|Furthermore} {cēnseō|I think} {iūs auctōris|copyright} {esse dēlendum|must be destroyed}.