Tenellia adspersa (von Nordmann, 1845)

Description

A tiny aeolid nudibranch reaching only about 5–8 mm in length. The body is translucent white, scattered with fine black to dark-brown spots — the "sprinkled" appearance reflected in the specific epithet. The cerata are short and stout and not arranged in tight rows. Both rhinophores and oral tentacles are smooth.

Distribution

Originally described from the Black Sea coast near Odessa, Ukraine. Subsequently recorded from the Baltic Sea, the north-western Iberian Peninsula, the British Isles and the Mediterranean, and now widely reported as an introduced species in brackish habitats around the world, including North America and Japan. Typically found in estuaries, harbours and low-salinity bays.

Etymology

The specific epithet adspersa is from the Latin adspersus, meaning "sprinkled" or "scattered upon", in reference to the fine dark speckling over the body.

Remarks

Feeds on hydroids — most notably the brackish-water Cordylophora caspia — and is often introduced to new regions as a hull-fouling associate.

---

References

• Tergipes adspersus, Nordmann A. von (1845). Versuch einer Natur- und Entwicklungsgeschichte des Tergipes edwardsii. Mémoires presentés à l'Académie des Sciences de St. Petersbourg par divers savans. 4: 495-602.
• Shirotae-minoumiushi (n. n.), Baba K. & Hamatani I. (1963). A SHORT ACCOUNT OF THE SPECIES, TENELLIA PALLIDA (A. & H.), TAKEN FROM MUKAISHIMA, JAPAN (NUDIBRANCHIA-EOLIDOIDEA). Publications of the Seto Marine Biological Laboratory. 11(2): 337-338. https://doi.org/10.5134/175340
• クロゴミノウミウシ（新称）, 西田和記. (2024). ウミウシの生態観察図鑑. 誠文堂新光社.