Thursday, October 29, 2015

Melibe Ghostly Nudibranchs for Halloween! Happy #SeaSlugDay 2015

Image photographed by Martin Buschenreithner. Borrowed from the US Slug Site! 
NUDIBRANCHS! Happy First Sea Slug Day!!

Given its proximity to Halloween and my propensity for sharing cool stuff about weird animals my post this week is about one of my favorite bizarre sea slugs: The ones in the genus Melibe!

Melibe (in the family Tethyiidae) includes 17 currently recognized species which are known Primarily from the tropical and temperate Pacific but with a minority of species from the Atlantic, including South Africa and the tropical west Atlantic (Bahamas, Florida, etc.)

Personal caveat: I am not an expert in nudibranchs and have gone with names used by the photographers. If you know better let me know and I will correct them.

Here's a "classic" Melibe leonina from the California coast to give you an idea of what the general body plan looks like...

This species is fairly well known. With nice brief write up by Monterey Bay Aquarium but many others as well. 
Melibe sea slug
When encountered, some species are often present in great abundance..

Although they appear to be mostly filter feeding in the pictures
Hooded Nudibranch
 some Melibe species can also be fairly effective predators.. here's a nice video from Japan showing prey capture..

Morphology on these animals is remarkable in that their body can be translucent to transparent and the internal anatomy can be visible just like those old "Visible Man" model kits!

A close up on the lobes on the body reveals these fine branching structures-the digestive glands! Which function in digestion of food
nudi branchia 1417

What happens when you take these digestive glands to the extreme? Along with a transparent body?
You get Melibe colemani, aka the "Phantom Melibe!" named for the photographer Neville Coleman, who was a noteworthy photographer, diver and natural historian from Australia.

What you are seeing in the picture below is its digestive glands!! The body is completely transparent!! This species was originally described from Malaysia. These images are from Lembeh (Indonesia) and other images have been identified from the Philippines, so I would imagine it occurs in roughly that tropical, central Pacific region. 

Nudibranch (Melibe Colemani)
Nudibranch (Melibe Colemani)
I know just looking at pictures doesn't look like its a sea slug, but check out this video!!
They SWIM!!
  Most of the species seem to crawl around or stay in one place, but given the motivation, some species can swim.. Here's what I think is Melibe viridis, based on this article in the Sea Slug Forum but kind of swimming in the water column..(identified as Melibe japonica, since synonymized)

Melibe diversity is fairly mind boggling.

This one from Lembeh, Indonesia. This one is also identified as Melibe viridis, but which seems to vary somewhat from the one from Japan. These can get quite large with some individuals reaching almost a foot long!

There's a nice write up on Melibe viridis here on the Slug Site. Here.
Lembeh_Melibe sp
Ugly Nudibranch
Ugly Nudibranch
Seeing this one alive is almost a necessity!

Melibe engeli from the Philippines
Melibe engeli
Melibe pilosa from the Philippines
Melibe pilosa.JPG
Melibe digitata from the Philippines
Melibe digitata

Wednesday, October 21, 2015

Japanese Invertebrates, Spirits & Monsters! Animals that inspire yokai (妖怪) & more!

Its October! Which means we are around the corner from Halloween! Many of you have seen how I have expressed a strong interest in Japanese science fiction and pop culture.  One of my starfish has even been made into a toy! 

My research over the last few years has taken me not only to Japan but also gotten me interested in the nomenclature of various Japanese starfish species!!

Although many of these are essentially common names, they are surprisingly standardized and are widely recognized in addition to the western Latin names.  While studying these I also encountered a few other cool stories about invertebrates which have been part of Japanese folklore and myth.

So this week: The Invertebrate-Japanese folklore connection! Names & monsters/spirits inspired by invertebrates!!

I thank Matt Alt of AltJapan and Dr. Toshihiko Fujita of the National Museum of Nature & Science for providing me with some of the the information in today's post!

1. The Oni Hitode
  So, the term yokai (妖怪) refers to a spirit or ghost , most of which have a strong root in Japanese folklore and myth. There are a great MANY types, some of which are listed here and Wikipedia of course!  Perhaps one of the types of yokai which I see popularly presented in pop culture and literature and in some Western sources is a demon called an Oni, of which one face is represented below...
Oni Mask
The spines on the head are a characteristic feature of this yokai. Its this characteristic which has most likely been lent to Acanthaster planci,  the crown of thorns starfish which is known in Japanese as the Oni Hitode or "Demon starfish" 鬼ヒトデ
Crown of Thorns
Here's another kawaii I found of the Oni-hitode, which from what I understand was part of a"Kill the crown of thorn starfish" campaign. Acanthaster planci, is a fairly well known predator of coral and has been undergoing massive population booms leading to frequent efforts to remove them.
From this Japanese site 
And of course, the inevitable transformation of the crown of thorns starfish into a kaijin or "human sized" monster to be defeated by a snorkel-adorned Kamen Rider! 

2. Higuruma Hitode (or not?)
Another cool Japanese starfish name is one this deep-sea brisingid starfish, Brisingaster robillardi.

I've described brisingid sea stars at length here. Deep-sea species which feed on prey in water currents using "velcro" (tiny claws) on their spines. More great images of these animals here.

The common name for this species is called the Higuruma Hitode which sounds GREAT! Hitode is Japanese for starfish. But What is a "Higuruma"??

Higuruma is apparently one name for a ghost/yokai called Kasha (whose name apparently translates to "flaming chariot" who carts the corpses of sinners off to the underworld (thanks to Matt Alt for this info). I suppose in this case the "corpses of sinners" are represented by small crustacean prey! Muahaha!

The resemblance between the flames (the arms) emerging from the wheel  (the disk) is how this starfish was likely named! Pretty neat!
Image from Dr. Fujita
To give you a better idea, here is a very similar "fire wheel" type yokai called Wanyudo, which translates to "wheel monk" and who apparently steals the souls of those who gaze upon it. Apparently many yokai can be similar in appearance

It also shows the "flames from wheel" appearance that this starfish takes after...
Image via the Yokai Attack! FB group
Interestingly, Higuruma hitode was actually assigned to a similar species called Novodinia pacifica so perhaps Brisingaster robillardi  should be referred to as a Wanyudo hitode or perhaps a Kasha hitode??

3. The Sazae-oni aka the "Snail Ogre" 栄螺鬼
This yokai is apparently one of the more malevolent ones and according to is a dangerous spirt that pretends to be a beautiful drowning woman in order to lure and feed on sailors.

There's a whole mythology about these yokai which involves pirates and monsters biting off their testicles.  You can read the colorful version here. 
Image by Toriyama Sekien via wikipedia and also this Japanese site
These yokai are actually based on horned turban snails, Turbo cornutus which look like this
#791 horned turban (サザエ)
These snails in Japan are called sazae (hence the name "snail demon"and are eaten throughout Japan, often grilled in their own shell
Sazae being grilled in IH Cooking Heater

This species of snail is widely familiar to the Japanese and was even made into a kaiju called Gogo in the show Ultra Q, the precursor to Ultraman!

4. Hekigani ヘイケガニ The "samurai crabs"(the crab Heikeopsis japonica)
This "ghost" is actually more of a ghost story. It basically relates the story of this crab, Hekeopsis japonica which often have a very human-like face on their carapace (i.e., the top side of the skeleton).
Heikegani 日本平家蟹
This species is referred to as the "samurai crab"?   Why? The "faces" on these crabs (actually the fine morphology of the carapace) have been thought to be the reincarnations of Japanese Heikie warriors defeated at the Battle of Dan-no-ura as told in The Tale of the Heike. Wikipedia has a nice summary of this event.

But here's a gorgeous painting which shows this event in various stages..
Image by Utagawa Kuniyoshi via Wikipedia
This crab species was also made famous by Carl Sagan who discussed them as an example of inadvertent character selection on Cosmos. You can watch this segment here

4a. The Kani-Oni: DEMON CRAB!! 
While doing research for this post I came across this creature, the Kani oni! aka the Crab Demon.   I couldn't find out much about it, but I did realize one thing..
 Thereare only THREE pairs of legs per side.  This is a characteristic feature of lithod crabs, which are actually more closely related to hermit crabs. "Proper crabs" such as the Japanese spider crabs have 4 legs on each side. 

But this species is very similar to this species, Lithodes aequispina (unconfirmed ID). Thus, the ghost crab does seem to be something in the Lithodidae. 
Golden King Crab (Lithodes aequispina)
The spines on the crab might allude to another species of lithode crab which has bigger and more prominent spines on the carapace, such as this one.
Paralithodes camtschaticus 5

5. The Umibōzu 海坊主
So this particular ghost isn't actually based on an invertebrate..but it gets honorable mention..

The name Umibozu translates to "Ocean or Sea, Buddhist Monk" and have been explained as the ghosts of drowned buddhist monks.  They are apparently haunted spirits of the ocean and mentioning their name invokes bad luck for ships at sea.
From all the accounts that I could find, there are apparently different "morphotypes" of what Umibozu look like with some images looking a bit more of a human shape...

The Umibozu tend to be rarely seen and considered somewhat mysterious..

I happened to notice a curious coincidence between these and Opisthoteuthis, aka one of the "dumbo octopuses"! But nah.. the umibozu are FAR more menacing! 


Tuesday, October 13, 2015

October 29th will be #SEASLUG DAY!!

Hypselodoris zephyra image by Steve Childs via Wikipedia
ATTENTION all photographers, divers, bloggers, scientists, natural historians, citizen scientists, museums, zoological parks, aquaria, big ocean organizations, and other colorful mollusk enthusiasts (in no particular order)! 

Let it be announced herein that October 29th of this year (Updated: Saturday-2016) will be SEA SLUG DAY!!  #seaslugday

So, why "sea slug" and not "nudibranch"? We're going to be focused primarily on nudibranchs, but there's actually a lot of different type of "sea slugs" which many people mistake for nudibranchs or which often get lumped in with them. A brief summary on these relationships are nicely written up on the Wikipedia page.

Sea hares for example are actually a distinct group from nudibranchs. But they are often regarded as "close" to nudibranchs.
Aplysia californica, California Seahare
So, to avoid "nudibranch VS. sea hare" or "nudibranch VS. sacoglossan"arguments and etc. I'm just going with "sea slug".  For the biologists out there: No, its not monophyletic. But its an easy catchall term. and the hashtag is slightly shorter than "nudibranchday".

Why October 29th for Nudibranch Day?
Nudibranch Day honors Dr. Terry Gosliner! Biologist at the California Academy of Sciences and one of the world's pre-eminent experts on nudibranchs!! Go here to see more about him October 29th is his birthday!
In addition to working on nudibranchs, Terry also coined the popular term "Bobbit Worm" for the raptorial polychaete Eunice sp. (many are E. aphroditois).

Why have a Nudibranch Day? Because they are fantastic animals and I just thought it was just LONG overdue. So I'm just doing it.  To be honest, there was an earlier attempt at "nudibranch week" here. But frankly, other than "during Shark Week" there's no fixed date indicated. Its also not my style to honor something by holding it up a contrarian force to something else. Positivity!!

We also have Halloween that weekend! I wouldn't mind at all if it extended out to Friday or even the weekend! To 'branch out as it were!! (ha!)

What better time to celebrate nudibranch diversity???

Wednesday, October 7, 2015

Some great Macro Shots of shallow-water Tropical Urchins!

So, after all that deep-sea stuff, I thought this week might be a good moment to look at some tropical, shallow-water species....

Stunning image of the cidaroid Plococidaris verticellata by Shawn Miller
Plococidaris verticillata, sea urchin

A fire urchin (probably Asthenosoma) from Puerto Galera, Philippines
Puerto Galera - Fire Urchin
More fire urchin love!
fire urchin

A magnificent anal sac in Astropyga
Seaa Urchin
Another anal sac from a diadematid urchin..

Details on Mespilia globulus!
Reaching Out

The slate pencil urchin Heterocentrotus mammilatus..or swirling maelstrom of the ELDER GODS?
Pencil urchin  - Heterocentrotus mammillatus
What lies beneath? the teeth from Aristotle's Lantern! 
Mouth of a Pencil Urchin