Last week we hit the 400th mystery object, which was this specimen from the Dead Zoo:

Horned beasties can be tricky since there are over 140 species in the Bovidae. There is quite a lot of diversity in size and in horn shape, but there are some general patterns, with spirals, twists, curves and recurves. A good place to trawl through for comparisons is the Animal Diversity Web, which has plenty of images.

However, this is one of the better known species, with nicely lyrate horns, so quite a few people recognised it without having to go searching. This is a Springbok Antidorcas marsupialis (Zimmermann, 1780), a South African antelope that has given its name to the nation’s rugby team. Well done to everyone who figured it out, particularly Goatlips, who got there first!

This specimen is one of 333 game heads that we’re in the process of decanting from the Museum, as part of a project that includes moving thousands of invertebrates and birds, as well as a couple of whales. If you’re interested in how we’re dealing with the game heads we recently reported on it at the NatSCA Conservation Twitter conference, which I’ve shared below:

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Last week I gave you this bumpy little critter to identify:

I think everyone recognised the mystery object as some kind of Nudibranchia or sea slug. The general type of sea slug is identifiable by that ring of gill filaments known as a branchial plume that you can see at the top of the specimen. This is characteristic of the suborder Euctenidiacea, also known as the dorids.

I called it bumpy, but if you look closely you’ll see that the bumps are pinched at the base and actually look rather warty. There’s a clue in that – and several of you spotted it.

There were a number of wart-related nudibranch suggestions that were close, but jennifermacaire was spot on with her comment:
Doris has warts?

This is indeed a Warty Dorid or Doris verrucosa Linnaeus, 1758.

This specimen isn’t quite as faded as everyone expected – they’re usually a fairly muted orange, yellow or a greenish colour, not too different to the mystery object. This probably serves as camouflage against the background of the Warty Dorid’s favourite food, the Crumb-of-bread Sponge, which also varies in colour from bright yellow to darker shades depending on the depth of the water in which they live.

More mystery objects next week!

Last week I gave you this mystery object to have a go at identifying:

Clearly it’s some kind of sea-star, but there are a LOT of different species .

Remarkably, that doesn’t seem to have posed a problem. The five stumpy arms narrowed it down to one of the cushionstars or biscuitstars and it seems that was more than enough for some of you.

Salliereynolds flagged one of the diagnostic features and dropped a hint to the species name:
“Six lumps to a side? From down under?”

But Goatlips took the mystery object to a whole new level with a biscuit recreation:

This specimen is a Southern Biscuit Star Tosia australis Gray, 1840. Probably not as tasty as an actual biscuit, but certainly very biscuity in appearance.

A short answer today I’m afraid, but it’s been a difficult week and there’s a lot to do in the Dead Zoo this Friday!

Last week I gave you this specimen from the Dead Zoo to have a go at identifying:

It was a bit mean of me to not include a scale, but several of you managed to work it out regardless.

The overall group is fairly easy to spot, since it has 10 legs, the front pair bearing claws (or chela if you want to get technical) and the main body area is rounded. So it’s a crab.

In addition, the long legs and small body give it an overall shape reminiscent of a spider, so it’s a good bet that it’s some kind of spider crab.

Now, there are quite a lot of types of spider crab out there, but that sub-triangular body shape and those long legs help narrow down the possibilities further. In fact, it does share some similarities to the gigantic Japanese Spider Crab.

Unlike the Japanese Spider Crab (which was suggested), this doesn’t have extremely elongated chela. So not one of them. It’s also way too small, although my lack of a scale bar doesn’t make that obvious – sorry! However, the mystery object is in the same family (the Inachidae).

Once you start looking at the genera in the Inachidae there’s only one that matches the mystery object’s proportions, and that’s the Macropodia. Once you get that far, it becomes a case of discounting possibilities based on much more detailed features.

The Marine Species Identification Portal is a fantastic resource for checking this finer level identification. Going through the various species descriptions in there helps spot the key features for distinction between species.

In this case, the mystery object is particularly similar to M. tenuirostris and M. rostrata and it’s mainly the shape of the carapace around the ‘shoulders’ where the chela attach to the body that help confirm this to be the Long-legged Spider Crab Macropodia rostrata (Linnaeus, 1761).

So it was a good effort for everyone who managed to get this to family level, I congratulate those who worked this out to the genus and I doff my hat to anyone who managed to identify it to species. So jennifermacaire, my hat is doffed!