Trapania lineata Haefelfinger, 1960
WoRMS Taxonomic Information
Current classification
| Superdomain | Biota |
|---|---|
| Kingdom | Animalia |
| Phylum | Mollusca |
| Class | Gastropoda |
| Subclass | Heterobranchia |
| Infraclass | Euthyneura |
| Subterclass | Ringipleura |
| Superorder | Nudipleura |
| Order | Nudibranchia |
| Suborder | Doridida |
| Infraorder | Doridoidei |
| Superfamily | Onchidoridoidea |
| Family | Goniodorididae |
| Subfamily | Anculinae |
| Genus | Trapania |
| Species | Trapania lineata Haefelfinger, 1960 |
The analysis of the radula and reproductive system revealed that T. hispalensis, T. pallida, and T. lineata share an identical structure in the denticles and radular formula, with no significant differences, although variations were sometimes observed even between the teeth of a single radula. The reproductive system structures, including the shape of the penis and the prostate gland, were also virtually identical across the three taxa. Genetic analysis based on mitochondrial and nuclear DNA sequences also confirmed that there were no significant genetic differences between T. hispalensis, T. pallida, and T. lineata. The specimens studied belonged to the same monophyletic clade with very low levels of genetic divergence, clearly indicating that they are part of a single species. T. pallida was somewhat genetically separated from the other two species, likely due to geographical isolation, but not enough to be considered a distinct species. However, recent findings of this species in the Mediterranean near local morphotypes suggest that it may not end as a different species in the future.
Synonyms
- Trapania hispalensis Cervera & García-Gómez, 1989
- Trapania pallida Kress, 1968
Description
This is a small dorid nudibranch with a limaciform, relatively thick body that can reach a maximum length of about 20mm, though it is usually around 10-15mm. The body is plump in its central area, with a translucent white base color that may allow the brown visceral mass inside to be visible. The dorsum is often decorated with fine, iridescent white lines running along the back, sides, head, oral tentacles, rhinophores, tail and, in certain cases, also along the axis of the branchial leaves. A distinguishing feature of this species is the presence of cylindrical extrabranchial and extrarinophoric appendages located on the external sides of the rhinophores and gills. These appendages are directed backward and slightly inward, with their distal tips, along with those of the rhinophores, gills, propodial palps, and tail, often colored yellow to yellow-orange, sometimes white (in former T. pallida morphotype). The rhinophores are relatively long and wide, featuring about 10-12 non-retractile lamellae at their distal portion, with the basal part matching the body color. The gill comprises three large tripinnate branchial leaves, with the central one being the largest. A small beige-colored anal papilla is located right behind the gills. The oral tentacles are finger-shaped and often pigmented yellow-orange, sometimes white. The foot is relatively narrow, matching the body color. The propodial tentacles are broad at the base, curved backward, and may be completely or partially yellow, sometimes white. The tail is pointed and may have an orange (sometimes white) tip.
Biology
It is commonly found on rocky substrates, often in dimly lit environments such as caves or overhangs with an abundance of sponges. It is usually associated with sponges of the genus Ircinia, habitat of the entoprocts (Kamptozoa) of the genus Loxosomella (Cattaneo-Vietti et al. 1990), small sessile invertebrates that grow on sponges that are its primary food source. The reproductive season occurs between March and June, with spawn consisting of a ribbon-like structure about 25mm long and 2mm wide, containing white eggs of approximately 80 microns in diameter. This species is often parasitized by copepods of the genus Splanchnotrophus, which attach near the gills and embrace the visceral mass.
Etymology
- Trapania. The original generic name of this species was Drepania, proposed by Lafont in 1874. Pruvot-Fol in 1931 proposed changing the generic name to Trapania to disambiguate it from Drepania Hübner, 1816 (a group of lepidoptera). Madame Pruvot-Fol does not indicate the origin of the name, but there are two theories: the first would be dedicated to the city of Trapani, the province capital of western Sicily; the second would be inspired on the original generic name Drepania, derived from the Greek “Drepane” which means “sickle” and presumably refers to the shape of the appendages located on the sides of the rhinophores and gills in this genus. Pruvot Fol would have chosen the new name on the basis that it has the same meaning, but not the same sound and thus avoid confusion.
- Lineata. From Latín “lineatus”, with lines, lined.
Distribution
This species is distributed throughout the northeastern Atlantic and the Mediterranean Sea. It has been recorded from the British Isles, Arcachon Bay (France) to the Strait of Gibraltar in the Atlantic, and across the Mediterranean, including France, Sardinia, Turkey, and the Iberian Mediterranean coast, including the Balearic Islands. Notable records exist from locations such as Es Caials, Cadaqués, L’Escala, Medes Islands, Palamós, Formigues Islands, Blanes, Mataró, and La Pineda (Salou).
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Abundance
| Western Mediterranean: | ★★☆☆☆ |
| Eastern Mediterranean: | ☆☆☆☆☆ |
| Atlantic Ocean: | ★☆☆☆☆ |
This chart displays the monthly observation probability for Trapania lineata based on our own records.
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Further reading
Cite this article as:
Pontes, Miquel (2025) "Trapania lineata" in OPK-Opistobranquis. Published: 15/05/2012. Accessed: 03/09/2026. Available at (https://opistobranquis.info/en/?p=412)
