Photo of the day (68): Tethys fimbria

Tethys fimbria is a big nudibranch in the family Tethydidae. My specimen is from Croatia and photos were taken in the aquarium:

Tethys fimbria have cerata on sides of its body. Dorsal view from its tail end:

Tethys fimbriaIt will self-amputate its own cerata, when it feels in danger. It is good defensive strategy against fish. But when people tries to catch a Tethys fimbria, then it can lose many of its cerata.

Self-amputated cerata of Tethys fimbria:

Cerata of Tethys fimbriaFrontal view of Tethys fimbria:
Tethys fimbriaIts rhinophores are small. The left rhinohore is that small brown thing:
Rhinophore of Tethys fimbriaIt is known, that species in the family Tethydidae are predators. They hunt small crustaceans. But I have never read which exact small crustaceans they eat. They use the oral velum or oral hood for catching the prey.

Oral velum from the ventral side:
Oral velum of Tethys fimbriaDetail of the oral velum from ventral side:
Detail of oral velum of Tethys fimbriaIf you know what species of crustaceans does Tethys fimbria hunt, let me to know. Thanks.

References

no

Advertisements

Photo of the day (65): Ocinebrina aciculata

Ocinebrina aciculata is a marine sea snail. It belong to the family Murididae. It lives in depth 0-105 m in the Mediterranean Sea and elsewhere. My snail is from Croatia.

The height of the reddish brown shell is up to 18 mm. The color of the whole animal is reddish: it has reddish foot, head, tentacles and siphon. I have taken the following photos ex situ in small aquarium for photography.

Right side view of crawling Ocinebrina aciculata:
Right side view of Ocinebrina aciculata
Ventral view of crawling snail:
Ventral view of Ocinebrina aciculata
Frontal view:
Frontal view of Ocinebrina aciculata
Abapertural view:
Frontal view of Ocinebrina aciculata
Apertural view:
Frontal view of Ocinebrina aciculata
Ocinebrina aciculata in my hand, just for size overview:
Frontal view of Ocinebrina aciculata

References

Crocetta F., Bonomolo G., Albano P. G., Barco A., Houart R., & Oliverio M. (2012). The status of the northeastern Atlantic and Mediterranean small mussel drills of the Ocinebrina aciculata complex (Mollusca: Gastropoda: Muricidae), with the description of a new species. Scientia Marina, 76(1), 177-189. doi: 10.3989/scimar.03395.02A

Photo of the day (63): Turbinella pyrum

Turbinella pyrum is a large marine predatory snail. It belongs to the family Turbinellidae. The shell length of this species up to 150 mm.

This specimen of shell has unusual appearance, because it is a shankha. Shankha shells are religious items used in Buddhism and Hinduism. It is on display in temporary exhibition The Story of Tibet in Náprstek Museum of Asian, African and American Cultures in Prague.

Shankha Turbinella pyrum shellThis shankha comes from Tibet or from Mongolia. It was used as a regilious ritual item in Tibetan Buddhism. The shell of this specimen is decorated with a metal plate, that gives the ability to use this shell as a trumpet.

References

Wikipedia contributors 2017: Shankha. accessed 29 July 2017.

Photo of the day (60): shell headdress from New Guinea

This is an original tribal ceremonial men’s feather and shell headdress from Tambanum village on the Sepik River, East Sepik Province, northern Papua New Guinea. It was made in 19th century. It was shown in the exhibition “Crown jewels in the world’s history” in Ostrava museum at December 9, 2016 – March 5, 2017. It comes from the private collection of goldsmith Jürgen Abeler, owner of the Wuppertaler Uhrenmuseum, that was closed in 2016. The headdress is in the collection of Juwelier Abeler company (juwelier means jeweler) in Wuppertal now. I was happy to see it because it was the only thing on the exhibition, that contained shells.

feather and shell headdressLeft side view:
feather and shell headdressLarger shells are some species from the family Cypraeidae. It is probably Monetaria moneta, a common species, that was used as a shell money in various parts of the world including the New Guinea.

headdressThe smaller shells are also from marine gastropods, but I did not identify the species. Some headbands and other things from the area contain the same shells that are called “Nassa shells”. This does not mean the genus Nassa from the family Muricidae. It may mean some species from the family Nassariidae, that are commonly known as “Nassa mud snails”.

Other things of the headdress include feathers of a cassowary (Casuarius). There exist three extant species of cassowaries and all of them live in New Guinea. All of them have black feathers. According to the locality of the headdress and the distribution of cassowaries, feathers probably comes from the northern cassowary (Casuarius unappendiculatus) or from the dwarf cassowary (Casuarius bennetti).

There are also used animal teeth and number of strings.

Right side view:
feather and shell headdressI also do not know what is the material, from which “eyes” of this headdress were made. It looks like the same thing on the ancestor’s figure.

Such headdresses were and are used to emphasize the status of the owner. They are worn usually in festivals.

One more oblique view:
feather and shell headdressThe headdress also closely resembles for example feathered headdress for ancestor’s skull made by Asmat people.

That’s all. And if you can identify those small shells, let me to know. Thanks.

Photo of the day (58): Pleurobranchus areolatus

Pleurobranchus areolatus is a sea slug from the family Pleurobranchidae.

It lives in Caribbean Sea, Brazil, Madeira and Canary Islands. Such distribution in western Atlantic and also in eastern Atlantic is called amphiatlantic (or amphi-Atlantic).

I thank my colleague Jessica Goodheart from the USA who kindly provided the photo.

This certain specimen of Pleurobranchus areolatus comes from Panama. You can find more information about sea slugs from Panama in her article “Identification guide to the heterobranch sea slugs (Mollusca: Gastropoda) from Bocas del Toro, Panama“.

This is the right side view of the slug. Its body is oval. There are numerous tubercles on the dorsum. Its rhinophores are in the frontal sinus. The gill is not visible because it is under the dorsum. There is also small internal shell inside the slug’s body, but the shell is not visible externally.

Pleurobranchus areolatus

Pleurobranchus areolatus from Panama by Jessica Goodheart, CC-BY-4.0

References

Goodheart J. A., Ellingson R. A., Vital X. G., Galvão Filho H. C., McCarthy J. B., Medrano S. M., Bhave V. J., García-Méndez K., Jiménez L. M., López G. & Hoover C. A. (2016). “Identification guide to the heterobranch sea slugs (Mollusca: Gastropoda) from Bocas del Toro, Panama“. Marine Biodiversity Records 9(1), p.56. doi:10.1186/s41200-016-0048-z

Photo of the day (56): Umbraculum umbraculum

Umbraculum umbraculum is quite large marine gastropod. It belong to the family Umbraculidae. It can grow up to 15 or 20 cm. The color may vary from yellow to brown or to red.

There are two populations worldwide. One population in Indo-West Pacific region and one population in east Atlantic and Mediterranean region. The later one was considered as a separate species Umbraculum mediterraneum. They are considered synonymous although there exist no review of the genus yet. My Umbraculum comes from Croatia and I have take following photos ex situ.

The shell is much smaller than the animal body. The shape of the shell is cap like or limpet like. The tip of the shell seems to be pointing in some direction sometimes, but the tip does not allow to identify the head region if the animal is retracted. The shell is always covered with some growths.

Umbraculum umbraculumThere are many tubercles on its mantle. Detail of tubercles:

Umbraculum umbraculumFoot is also circular even when the animal is crawling:
Umbraculum umbraculumThere is a gill on the right side of the body just below the shell. There are visible lamellae of the gill under the shell.
Umbraculum umbraculumIts dark eyes are between tentacles (rhinophores).
Umbraculum umbraculumI was no lucky to get a proper photo of its frontal slit region, that contain mouth and permanently protruded penis. Maybe next one.

Umbraculum umbraculum feeds on sponges (Porifera) from the class Demospongiae. Yes, SpongeBob should be afraid of this snail beast! Other ones can enjoy this snail species, because it certainly awaits for further interesting discoveries.

References

Rudman W. B., (1999 January 14) Umbraculum mediterraneum (Lamarck, 1819). Sea Slug Forum. Australian Museum, Sydney. accessed 2016 October 14.

Rudman W. B., (1999 March 7) Umbraculum umbraculum (Lightfoot, 1786). Sea Slug Forum. Australian Museum, Sydney. accessed 2016 October 14.

Photo of the day (53): Bolma rugosa

Bolma rugosa is a marine snail in the family Turbinidae. It is quite a big snail with a shell length up to 70 mm. Locality of my snail is Croatia. I have taken the following photos ex situ in the aquarium.

Bolma rugosaThose pointed structures bellow the shell are sensory structures, that are called epipodial tentacles. They are common structures in Vetigastropoda (one of main groups of gastropods).

Detail of epipodial tentacles:

epipodial tentacles of Bolma rugosaFoot view of Bolma rugosa:

Bolma rugosaFew other photos by other authors also shows epipodial tentacles on Bolma rugosa:

https://www.flickr.com/photos/o_torrents/5880559472/ at the top right corner of the photo.

or on the Circolo Attività Subacquee Chieri (Diving Club in Chieri, Italy) website at http://www.casc.it/VisPhotogallery.asp?Page=0&P=1&S=3051&F=1805&D=Bolma%20rugosa%2004.jpg

References

Wanichanon C., Laimek P., Chitchulanon N., Suphamungmee W., Apisawetakan S., Linthong V., Sretarugsa P., Kruatrachue M., Upatham E. S., Poomtong T. & Sobhon P. (2004). Sensory receptors on cephalic and epipodial tentacles of Haliotis asinina Linnaeus. Journal of Shellfish Research, 23(4): 1097-1106.

Photo of the day (52): Tonna galea

Tonna galea is a large sea snail with worldwide distribution in temperate and in tropical seas. I have taken these photos in Croatia.

Tonna galea one of the largest snails in the Mediterranean Sea. Because of its size and because its beautiful shell it is exploited or over-exploited as a food source and as a tourist souvenir.

This species is protected by 1979 Berne Convention on the Conservation of European Wildlife and Natural Habitats as a strictly protected species. Therefore is is protected by law in many European countries. For example in Croatia it is protected since 2013 by law. It is forbidden to capture, kill, trade, import, export, and so on.

Despite its protection, its population size is thought to be greatly declined. Exporting of empty shells abroad is also not allowed. Let them for local residents and maybe they will use them in some nice way like this:

Tonna galea
With Haworthia sp.:

Tonna galea
With Aloe sp.:

Tonna galea
References

Doxa C. K., Sterioti A., Kentouri M. & Divanach P. (2011). “Encapsulated development of the marine gastropod Tonna galea (Linnaeus, 1758) in captivity“. Journal of Biological Research 16: 304–307.

Katsanevakis S., Lefkaditou E., Galinou-Mitsoudi S., Koutsoubas D. & Zenetos A. (2008). “Molluscan species of minor commercial interest in Hellenic seas: Distribution, exploitation and conservation status“. Mediterranean Marine Science, 9: 77-118.

(1979). Berne Convention. Annex II.

(in Croatian) (2013). “Zakon o zaštiti prirode. [Nature Protection Act]”. Narodne novine«, broj 80/2013 [Official Gazette 80/13].

Photo of the day (50): Flabellina affinis

Flabellina affinis is a species of a nudibranch (Nudibranchia). Some nudibranchs really breathe by naked gills, but this species belong to a group of nudibranchs, that breathe by the whole body surface.

It is common species in the Mediterranean Sea. It feeds on colonial hydrozoids from the genus Eudendrium. It live in rocky habitat in the sublittoral zone not far from the shore.

I have taken photos in the lab (ex situ), so we take take a look at some anatomical features. Flabellina affinis can reach up to 50 mm, but my specimen is much smaller, about 20 mm. It is pink.

Flabellina affinisIt has a pair of tentacular foot corners (foot tentacles) – the most lower ones. It has a pair of labial tentacles (they are called as oral tentacles in other slug species). The top one ear-like structures are called rhinophores. There is visible small dark eye on the photo above. Eye is more likely on the base of rhinophores than on the base of labial tentacles.

Frontal view of the slug:

Flabellina affinisThe slug has cerata on its body. Cerata are in groups. There are from six to nine groups of cerata on the right side and on the left side of the body. My slug has seven groups of cerata, but the sixth group and the seventh group are not paired.

Flabellina affinisThe slug is small and it can crawl on the water level in the laboratory conditions. So there is also foot or ventral side visible on photos sometimes. There are visible genital apertures bellow the first group of cerata on the right side of the body on the following photos. They looks like two small tubercules. There is visible anus as a black dot on the right side between the first and second group of cerata. Anus looks like a small pointed tubercule:

Flabellina affinis

Flabellina affinisThere is a dark structure between the first and the second group of cerata, but I do not know what it is:

Flabellina affinis

Flabellina affinisReferences

Schulze A. & Wägele H. (1998) “Morphology, anatomy and histology of Flabellina affinis (Gmelin, 1791) (Nudibranchia, Aeolidoidea, Flabellinidae) and its relation to other Mediterranean Flabellina species“. Journal of Molluscan Studies 64(2): 2195-214. doi:10.1093/mollus/64.2.195

Photo of the day (48): Pisania striata

Pisania striata is a marine snail in the Buccinidae family. It is a common species in the Mediterranean Sea. It is a scavenger or predator, but I found no detailed information about its food. Its habitat include rocky seashore (eulittoral zone or intertidal zone) and in the sublittoral zone not far from the shore (subtidal zone).

The height of the shell is up to 30 mm. There are fine spiral striae on its shell sculpture. The specific name striata is derived from those striate.

This one is from the Dubrovnik-Neretva County, southern Croatia. I have taken this photo in situ in very shallow water (about 2-3 cm) with an ordinary non-water-proof camera. Maybe it can be a motivation for anybody to take photos of marine animals with any camera. You just need to take care about reflections from the water level.

Its body is black. It extend its siphon through the siphonal notch during crawling, because there are chemoreceptors in the siphon and the snail is searching for its prey:

Pisania striata in situDetail of the snail:

Pisania striataApertural view shows, that its foot and some parts of its body are surprisingly light gray:

apertural view of Pisania striataYou can also compare the length of its siphon with tentacles:

foot of Pisania striataAnother view shows that the shape of its operculum is like a droplet:

a live Pisania striataReferences

Dance S. P. (ed.) (1974). The Encyclopedia of Shells. Blanford Press, ISBN 0713706988, page 145.