Stiliger llerae Ortea, 1982
- Stiliger llerai Ortea, 1982
Description
The largest observed specimens measured 5 mm, although the average size varies between 2.5 and 4 mm when extended. Body color varies from orange-yellow to bottle green on back and basal part of cerata. The rhinophores are long, each measuring more than twice the width of the head, they are auriculate and with a pointed apex, which is dark blue in color, while the base is white. The eyes are black, and are located behind the rhinophores. The head has a large triangular black mark located between the eyes, with the base of the triangle directed forward and the vertex touching the cardiac area. This spot is a characteristic trait of this species. The foot is yellow in color, has two anterior lobes and is very broad, protruding widely on the sides of the head while it is only slightly visible on the back of the body when the animal directs the cerata upwards, but completely hidden when the animal directs the cerata towards the back. The cardiac area is large and bulging. The anus opens at the end of a long papilla located at the end of the rectum, which reaches the center of the cardiac area from its anterior side and is attached to it. The renal pore opens dorsally at the base of this papilla, just at the point where it is clear of the surface of the cardiac area. The cerata are characterized by having a globose shape, more or less elongated. They are distributed in a maximum of ten transversal series throughout the body and posterior zone of the cardiac area, being smaller towards the sides than in the center. The cerata always have a dark apical point, located in the center of a yellow-orange subapical zone, under which there is a bright blue ring. The rest of the cerata varies, like the color of the body, between yellow and green depending on the amount of food ingested by the animal. In the rearmost cerata the blue ring is somewhat wider than in the anterior ones. Inside the cerata, the digestive gland can be seen as an unbranched central duct. The penile opening is located on the right side of the body, between the eye and the rhinophore on that side.
Biology
Stiliger llerae lives on the algae Codium adhaerens on which it feeds and reproduces, in mesolittoral and infralittoral tidal zones. It has never been found on Codium tomentosum or on the other Codium species present in the area. The egg-spawn takes place, at least, in July and August, and is made up of a thick cord of 3 mm in diameter and circular section, rolled into a spiral of slightly more than one turn. The eggs, about 122 microns in average size, are white and appear coiled in a helical shape.
Etymology
- Stiliger, from Latin stylus, needle, pen, probe and the Latin verb gero, gerere, to bring, to carry.
- Llerae, in honor to the author’s wife, the biologist Eva María Llera.
Distribution
This species is only known from the Macaronesia, having been reported in the Canary Islands (Spain) and in the Salvages (Portugal) only.
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Abundance
Western Mediterranean: | ☆☆☆☆☆ |
Eastern Mediterranean: | ☆☆☆☆☆ |
Atlantic Ocean: | ☆☆☆☆☆ |
More pictures
Bibliography
Further reading
Cite this article as:
Pontes, Miquel (2023) "Stiliger llerae" in OPK-Opistobranquis. Published: 13/12/2022. Accessed: 07/06/2023. Available at (https://opistobranquis.info/en/DuWdz)