{"id":262,"date":"2012-05-14T21:27:42","date_gmt":"2012-05-14T19:27:42","guid":{"rendered":"https:\/\/opistobranquis.info\/elysia-traslucenselysia-traslucenselysia-traslucens"},"modified":"2025-04-08T14:30:40","modified_gmt":"2025-04-08T12:30:40","slug":"elysia-translucens","status":"publish","type":"page","link":"https:\/\/opistobranquis.info\/en\/guia\/sacoglossa\/plakobranchoidea\/elysia-translucens\/","title":{"rendered":"Elysia translucens"},"content":{"rendered":"

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Elysia translucens<\/em> (Pruvot-Fol, 1957)<\/h3>\n

\"Elysia<\/div>
Elysia translucens @ L'Escala<\/em> by Enric Madrenas<\/center><\/span>

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WoRMS Taxonomic Information<\/h3>
Current accepted name: Elysia translucens<\/em> Pruvot-Fol, 1957<\/strong><\/div>

Current classification<\/h4>
Superdomain<\/th>Biota<\/a><\/td><\/tr>
Kingdom<\/th>Animalia<\/a><\/td><\/tr>
Phylum<\/th>Mollusca<\/a><\/td><\/tr>
Class<\/th>Gastropoda<\/a><\/td><\/tr>
Subclass<\/th>Heterobranchia<\/a><\/td><\/tr>
Infraclass<\/th>Euthyneura<\/a><\/td><\/tr>
Subterclass<\/th>Tectipleura<\/a><\/td><\/tr>
Superorder<\/th>Sacoglossa<\/a><\/td><\/tr>
Superfamily<\/th>Plakobranchoidea<\/a><\/td><\/tr>
Family<\/th>Plakobranchidae<\/a><\/td><\/tr>
Genus<\/th>Elysia<\/em><\/a><\/td><\/tr>
Species<\/th>Elysia translucens<\/em> Pruvot-Fol, 1957<\/a><\/td><\/tr><\/table>

Classification provided by the World Register of Marine Species (WoRMS). [139685<\/a>]<\/p><\/div>Taxonomic status:<\/strong> Taxon inquirendum<\/em> (according to MolluscaBase, 2024)<\/p>\n

Taxonomic Note:\u00a0<\/strong>Regarding the validity of Elysia translucens<\/em>, Mart\u00edn-Herv\u00e1s et al. (2024) reviewed the literature on this species. The original description by Pruvot-Fol (1957) was based on a specimen from Banyuls-sur-Mer, France (Mediterranean Sea), preserved in formalin. This specimen exhibited a completely translucent appearance, which led the author to tentatively propose it as a new species, albeit without full certainty. However, the distinct appearance of this individual\u2014compared to other E. viridis<\/em> specimens that the author had also fixed in formalin\u2014ultimately resulted in the designation of E. translucens<\/em> as a separate species. Other studies have shown that E. viridis<\/em> specimens can exhibit a wide range of colors, including dark green, light green, brown, yellow, or nearly white, depending on their most recent diet and feeding time (Rauch et al. 2018). The type specimen may have undergone prolonged starvation before being collected, which, combined with the fixative effect of formalin, could explain its translucent appearance.\u00a0Mart\u00edn-Herv\u00e1s et al. (2024) also examined published radular illustrations from other authors (Bouchet 1984; Thompson & Jaklin 1988), but the results were inconclusive, despite certain radular differences. They concluded that these variations in radular morphology could be diet-related, as previously reported for E. viridis<\/em> (Jensen 1993; Rauch et al. 2018). Additionally, externally, the E. translucens<\/em> specimen illustrated in Bouchet (1984) closely resembles E. rubeni<\/em> and E. margaritae<\/em>, and it is depicted on Flabellia petiolata<\/em>, a substrate also associated with E. rubeni<\/em> (Mart\u00edn-Herv\u00e1s et al. 2020). The drawing of E. translucens<\/em> in Thompson & Jaklin (1988) does not provide diagnostic features, as it is identical to E. viridis<\/em> in Thompson (1981). Moreover, based on their descriptions, specimens identified as E. translucens<\/em> from the Adriatic and Aegean Seas could belong to almost any Elysia<\/em> species, and the illustration of a juvenile specimen in Thompson & Jaklin (1988) more closely resembles E. rubeni<\/em>.\u00a0Unfortunately, no external or radular morphological description is available for the specimen identified as E. translucens<\/em> in the molecular analysis by Christa et al. (2014), which also was collected from Banyuls-sur-Mer. However, all specimens from this locality analyzed by Mart\u00edn-Herv\u00e1s et al. (2024)\u2014including the GenBank sequence\u2014clustered with E. gordanae<\/em> specimens from other Mediterranean locations.\u00a0Given the current information on E. translucens<\/em>, it remains unclear whether it represents a distinct species. Consequently, it should be considered a taxon inquirendum<\/em>.<\/p>\n

Description
\n<\/strong>Body elongate, soft, and dorsoventrally flattened. Entirely colorless and translucent under magnification, including the pericardial hump, rhinophores, tail, foot, and digestive diverticula. Only two pigmented features are visible: the black, pyriform eyes and a thin, snow-white marginal line along the parapodial edges. Rhinophores are short, rolled laterally, and unpigmented. Parapodia are wide and clear, displaying only the white edge. The foot is broad, smooth, and completely transparent. The digestive gland, typically greenish in other Elysia<\/em> species due to retained chloroplasts, lacks any pigmentation.\u00a0Due to the transparency, some internal structures are faintly visible: The buccal bulb is very small (it is much bigger in E.viridis). The radular morphology is distinctive: the teeth are much smaller and more pointed, with a differently shaped base, a more prominent lateral “spur” (\u00e9p\u00e9ron), and a stronger, coarser central cusp serration visible under lower magnification.<\/p>\n

Biology
\n<\/strong>No live observations of Elysia translucens<\/em> have been properly confirmed so far. The true species is known only from the preserved type specimen. Based on related Elysia<\/em> species, it is likely benthic and associated with shallow-water macroalgal habitats. Feeding is presumed to be suctorial on algal cells; however, no signs of kleptoplasty (retention of chloroplasts) were observed, which may be due to species-specific traits, or the effects of starvation, or preservation. Pruvot-Fol rejected the hypothesis of postmortem depigmentation, noting that other E. viridis<\/em> specimens from the same batch retained their coloration and that the E. translucens<\/em> specimen appeared fully developed. This suggests the lack of pigmentation is a natural trait and not an artifact.<\/p>\n

Etymology<\/strong><\/p>\n