Tritonia hombergii Cuvier, 1803

Description

The largest tritoniid nudibranch, reaching over 200 mm (up to 300 mm) in body length. Body broad, with a relatively few to moderate number of distinct branched dorsolateral appendages along the indistinct notal edge. Rhinophoral sheaths closed, lacking a lateral opening. Oral veil bilobed, bearing numerous long processes. Jaws oval; masticatory edge furnished with strong conical or elongate bristle-like elements. Central radular teeth tricuspid. Many rows of lateral teeth, more than 50 (up to 200) per half row. Coloration ranges from translucent white in juveniles to dark purplish-brown in fully grown specimens, becoming progressively darker with age.

Distribution

North-eastern Atlantic, from Norway and the British Isles southwards to Spain and the western Mediterranean.

Etymology

The specific epithet honours Wilhelm Guillaume Homberg (1652–1715), the German-Dutch-French chemist and natural philosopher.

Remarks

Type species of the genus Tritonia Cuvier, 1798. Feeds on the soft coral Alcyonium digitatum (dead man's fingers). Korshunova & Martynov 2020 restricted Tritonia to a clade of large-bodied tritoniids with bilobed oral veil bearing numerous processes and high lateral-tooth counts (typified by T. hombergii); they confirm the taxonomic identity of the neuroscience model species T. tetraquetra as a related congener. Pale juveniles were historically described as a separate species before being recognised as conspecific.

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References

• Tritonia hombergii, Korshunova, T. & Martynov, A. (2020). Consolidated data on the phylogeny and evolution of the family Tritoniidae (Gastropoda: Nudibranchia) contribute to genera reassessment and clarify the taxonomic status of the neuroscience models Tritonia and Tochuina. PLOS ONE 15(11): e0242103. doi:10.1371/journal.pone.0242103