Photo of the day (70): Parmarion martensi

This land gastropod is Parmarion martensi. It belongs to family Ariophantidae. Some gastropods from this family has a reduced shell. The shell can be so small in some Ariophantidae species, that they can not retract into it. Such gastropods are called semi-slugs.

I thank my friend Doubravka Požárová, the botanist from Charles University in Prague, who kindly provided the following photos to readers of this blog:

Parmarion martensi

Dorsal view of Parmarion martensi from eastern Bali. Photo by Doubravka Požárová, CC-BY-4.0.

Parmarion martensi

Left side view of Parmarion martensi from eastern Bali. Photo by Doubravka Požárová, CC-BY-4.0.

Photos were taken in the surrounding of Lempuyang Temple (Pura Lempuyang Luhur) in the eastern Bali, Indonesia in 2014. It was crawling on the road. I identified the species according to photos only.

Parmarion martensi can reach body length up to 45 mm. It has caudal horn on its tail, but it is not clearly visible on this photo. This species is very variable in color.

Parmarion martensi is native to Southeast Asia. Unfortunately it is able to spread by human activies. It has established in Fiji, Samoa and Hawaii. It was also recorded in the USA. It can be a pest on agricultural crops, but not serious one. Moreover it can transfer nematode Angiostrongylus cantonensis, that can cause human disease. Therefore it is an important species and for example it is quarantine species in the USA.

References

Brodie G. & Barker G. M. (2012). “Parmarion martensi Simroth, 1893. Family Ariophantidae“. ‘USP Introduced Land Snails of the Fiji Islands Fact Sheet Series’, No. 1

Cowie R. H., Dillon R. T., Robinson D. G. & Smith J. W. (2009). “Alien non-marine snails and slugs of priority quarantine importance in the United States: A preliminary risk assessment”. American Malacological Bulletin 27: 113-132.

Hollingsworth et al. (2007). “Distribution of Parmarion cf. martensi (Pulmonata: Helicarionidae), a New Semi-Slug Pest on Hawai‘i Island, and Its Potential as a Vector for Human Angiostrongyliasis“. Pacific Science 61(4): 457-467. doi:10.2984/1534-6188(2007)61[457:DOPCMP]2.0.CO;2

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Photo of the day (69): Vitrina pellucida

Vitrina pellucida is a small land snail in the family Vitrinidae. It is widely distributed in the Holarctic and it is very common species.

There is visible mantle appendix (extension of the mantle that slightly cover the shell) and open pneumostome (breathing pore) on the photo:

Vitrina pellucidaYou can find them in autumn much more easily. They are fully grown up to 10 mm in body length in autumn. Then they will lay eggs and die. The next generation will hatch out from eggs at spring. Therefore you can not usually find adult Vitrina pellucida at (late) spring (depending on country).

I was mushroom hunting in Moravia on October 14, 2017. I found this snail altogether with two juvenile Lehmannia marginata slugs on a Xerocomellus chrysenteron mushroom.

Vitrina pellucida and two Lehmannia marginataVitrina pellucidaDoes the Vitrina pellucida eat mushrooms? I do not know. But what does it eat?

British malacologist John William Taylor (1845-1931) wrote in 1914: “Vitrina pellucida has an almost omnivorous appetite, and is credited with feeding upon Liverwort (Jungermannia platyphylla), mosses, fallen leaves, and decaying vegetable matter. It is also carnivorous, being said by Dr. Baudon to voraciously devour raw mutton, and will also feast upon the bodies of dead or dying worms and animals of its own or other species.”

Falkner et al. wrote in their dataset in 2001:
Deciduous forest litter 2
Lichens (gen.) 1
Epilithic/epiphytic 1
Living algae 1
Higher plants (gen.) 2
Dead 2
Carnivorous/saprophagous 2

This can be read (approximately) in human language: Vitrina pellucida eat sometimes deciduous forest litter and dead plants. It is sometimes carnivorous and/or saprophagous. Rarely it also feeds on epilithic and/or epiphytic lichens and on living algae.

Both authors does not mention fungi. Falkner at al. ignored information, that it eats mosses (although mosses have its own column in the dataset and although they cited Taylor in the reference section), but they listed lichens. Among hundreds of references listed at the end on the book only, it impossible to practically detect where informations comes from.

References

Falkner G., Obrdlík P., Castella E. & Speight M. C. D. 2001: Shelled Gastropoda of Western Europe. München: Friedrich-Held-Gesellschaft, 267 pp.

Horsák M., Juřičková L. & Picka J. 2013: Měkkýši České a Slovenské republiky. Molluscs of the Czech and Slovak Republics. Kabourek, Zlín, 264 pp. (in Czech and English). page 112 and page 34.

Taylor J. W. 1914″ Monograph of the land and freshwater Mollusca of the British Isles. Zonitidae, Endodontidae, Helicidae. Leeds, page 7.

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

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Photo of the day (67): Limax cinereoniger

Limax cinereoniger is a big land slug in the family Limacidae.

I found this one underside the mushroom in the wood in Moravia, Czech Republic:
Limax cinereonigerAlthough it is thought to be the longest land slug species, it is shrinked like this:
Limax cinereonigerIt seemed a bit pale and especially the foot was very pale. I have taken it and taken no photo of the foot. It has great color variability, but the mantle is unicolor always and the sole has three color parts always.

I have taken photos of the same specimen 26 days later. It grow up and the three color parts of the foot are visible more clearly:

Limax cinereoniger footLimax cinereoniger foot with a ruler:

Limax cinereoniger footDetail of the foot:

Limax cinereoniger foot detailGeneral view:

Limax cinereonigerReferences

Horsák M., Juřičková L. & Picka J. 2013: Měkkýši České a Slovenské republiky. Molluscs of the Czech and Slovak Republics. Kabourek, Zlín, 264 pp. (in Czech and English). page 115.