Friday mystery object #314 answer(ish)

Last week I gave you this guest mystery object, courtesy of Joseph van Sambeek:

Mystery object. Image by Joseph van Sambeek, January 2000

The bony struts reinforcing thin plates of bone show it’s from something that lives in water all the time and which lacks lungs – you can tell this because this structure is what you get when you’re dealing with forces moving in a variety of directions, rather than mainly dealing with the constant force of gravity or compensating for buoyancy that is unavoidable when you live in water, but have lungs.

This means that many of you recognised it as being the neurocranium (that’s the bit of the skull that surrounds the brain) from a fish – more specifically from Sarah Gibson:

The first image is the skull roof, showing the elongated frontals and parietals (front of snout is left in first three images). Second image is a left lateral view, showing the internal parasphenoid that would pass between the two eye sockets. Third image is a ventral view, showing the bottom of the parasphenoid. And obviously last image is posterior view, showing the foramen magnum where the spinal cord would pass through, over the occipital condyle. It just may not look like a skull to some because it’s missing the eye sclera bones, jaws, cheek bones, pretty much anything that is not the skull roof or braincase.

However, as we all know, there are a LOT of different sorts of fish – around 33,600 described species and counting. This can make fish a nightmare to identify. However, there are some great resources out there, like Osteobase which has a very useful identification guide for various elements of a range of fish.

Alas, Osteobase didn’t have anything that fits this mystery specimen, so narrowing down to a species is rather difficult. I had the advantage of knowing that the specimen was collected in Baja California, although that was of little help in trying to get in an approximate area of the fishy family tree based on morphology, and there are still a ridiculous number of fish species is the area.

Sarah Gibson suggested that it may be a Barracuda, and it certainly fits in many aspects, but the shape of the frontals and parietals and details of the point of connection between the parasphenoid (that’s the bottom bar bit you see in the side view) don’t quite fit.

I had almost given up hope, when it occurred to me to concentrate on understanding the unusually large occipital condyle that Allen Hazen noticed, which suggested that it might be a taxon with an extremely extended rostrum (like the paddlefish or swordfish that Jennifer Macaire suggested) but with a weedier body and defined neck region since there would be no need for such a large articulation in a fusiform fish (they’re the muscular type that taper at both ends and have no neck, so don’t move their heads).

With this bizarre sounding fish in mind I was able to fairly rapidly narrow down the possibilities to one of the three species of cornetfish that live in the Pacific. I was delighted to find some great images of the skull of a Red Cornetfish, which matches the morphology very well.

Red Cornetfish Fistularia petimba from the Gulf of Mexico. Image by SEFSC Pascagoula Laboratory; Collection of Brandi Noble, NOAA/NMFS/SEFSC

Red Cornetfish Fistularia petimba from the Gulf of Mexico. Image by SEFSC Pascagoula Laboratory; Collection of Brandi Noble, NOAA/NMFS/SEFSC

However, the Red Cornetfish doesn’t really occur in the eastern Pacific, so it’s very unlikely to be that species. The Reef Cornetfish does occur in the eastern Pacific, but has only been reported in Californian coastal waters since November 2015 and this mystery specimen was collected back in January 2000 (which doesn’t make it impossible to be a Reef Cornetfish, just very unlikely). Which leaves us with the most likely identification (although by no means confirmed) of Deepwater Cornetfish Fistularia corneta Gilbert & Starks, 1904.

These long, thin fish can reach up to 2m, but they have tiny mouths that limit them to eating crustaceans, marine worms and smaller fish that they pick up from near the surface of reefs and the sea bed – presumably being harder to spot as a predator thanks to their very small frontal projected area.

I’ve asked Joe to check his specimen against the images of the cornetfish, since there’s nothing better than having a specimen in your hand when attempting an identification.

I hope you enjoyed the challenge!

Friday mystery object #282 answer

Last week I gave you this mystery object supplied by Dr David Hone:mystery282

This is the premaxilla of a fish, but that doesn’t narrow things down much, since there are 28,000 species of bony fish, leaving a huge range of possibilities.

There were several suggestions of Wolf Fish, which is what I originally thought it was myself, but that’s not what it is. Then the suggestions of various Wrasse species started cropping up – which is a lot more likely.

My first look at Wrasse teeth came when I tried to identify the fish used in the Horniman’s Merman:

SONY DSC

There are a lot of Wrasse, over 600 species in fact, so it can be hard to narrow down the species, especially when few comparative specimens are available.

One very helpful osteology resource for identifying fish from their bony bits is Osteobase which lets you pick a bone and start making comparisons. It’s worth keeping in mind that you need to really explore the taxonomic tree on the left of the page to get a real appreciation of how useful it is – so for example, after selecting the premaxilla, if you look at the Perciformes (the Order containing the Wrasse) you see a huge range of premaxilla specimens that help narrow down the bone you’re trying to identify.

This clearly shows that the Labridae is definitely the right family for the mystery object and the Mexican Hogfish Bodianus diplotaenia (Gill, 1862) is a very close match.

So congratulations to Richard Lawrence who I think has it right, especially since the specimen was found within the range of this species. I hope you all enjoyed the challenge!

Friday mystery object #263 answer

Last Friday I gave you this mystery object that came up at a natural materials identification course that I delivered at the Royal Albert Memorial Museum in Exeter last week:

mystery263

There were a variety of suggestions as to what it might be, but everyone (correctly) discounted the information on the label that it was a tooth.

There were some suggestions of wood and ivory, but there were two suggestions which were definitely in the right ball-park. Daniel Calleri suggested it might be something fishy, while Krista got it pretty much spot on when she suggested a dorsal barb from a skate or ray.

I’m pretty sure that it’s the spine from the leading edge of the first or second dorsal fin of a Spurdog shark in the genus Squalus Linnaeus, 1758.

Spiny Dogfish (Squalus acanthias) by Dornhai

Spiny Dogfish (Squalus acanthias) by Dornhai

These turn up every so often in collections, sometimes as decoration, sometimes as items found in Native American middens. Presumably they’re composed of keratin, which is a commonly occurring structural protein in vertebrate skin that can also form hair, horn, scales and claw.

Thanks for all your comments and well done to Krista!

Oddjects No.1

I’ve been running my mystery object for over three years now and I’ve decided to add another kind of post in order to share some of the odd and interesting objects that I come across as I work in the collections of the Horniman Museum.

To share these specimens I’ve chosen the name ‘Oddjects’ as a portmanteau of ‘Odd’ and ‘Objects’. Here’s the first:

Oddject1

This happens to be a Wolffish (Anarhichas sp.) specimen that was a mystery object back in 2010, but here I just want to use the specimen to capture the imagination and spark discussion rather than provide much in-depth interpretation.

What does this make you think of?

I hope you enjoy the Oddjects I plan to share – if you do I would heartily recommend also checking out the Twitter and Tumblr feeds for the Horniman’s collections review projects as they also share some great objects.

Friday mystery object #169 answer

On Friday I gave you this specimen to identify:

It was one of those specimens that if you’d seen one before it was easy, if not it’s quite hard to work out.

In gross shape the skull has some similarities to that of a reptile, perhaps something like a Monitor lizard (albeit a little narrower). However, it actually belongs to a fish.

Cam Weir recognised this and managed to identify the kind of fish to genus and then species level, along with henstridgesj, 23thorns, Barbara Powell and Robin. Leigh and Ethan were also in the right ball-park with their identifications. This is the skull of the  Continue reading

Friday mystery object #128 answer

Happy New Year!

On Friday I gave you this piece of an animal to identify:

As expected, you managed to work out what it is in fairly short order.

Jake recognised it as skin, Denis Copilas as scales and Rhea as carapace – all of which are right at least in part. Henstridgesj and Barbara Powell’s friend Alison spotted that the section of carapace came from a Cowfish or Boxfish. There wasn’t really enough information available to identify it any further than that.

Fortunately this specimen had a label associated with it, so I can tell you that the section of carapace is from the  Continue reading