Kremer, L. P.; Metri, R.; Rocha, R. M. (2011). Description of Sidneioides peregrinus sp. nov. (Tunicata: Ascidiacea: Polyclinidae): a possible exotic species in the Atlantic Ocean. Zoologia. 28(6), 784-788.
Description of Sidneioides peregrinus sp. nov. (Tunicata: Ascidiacea: Polyclinidae): a possible exotic species in the Atlantic Ocean
Zoologia
28(6), 784-788
Publication
Available for editors
Three species of Sidneioides Kesteven, 1909 were known until now, all of them from the western Pacific.
Sidneioides peregrinus is a new species we found in Paranaguá Bay, southern Brazil. Diagnostic characteristics of the
species are: colonies with 1-5 lobes, closely clumped, and attached by the entire basal area or by a common smaller
area; seven to ten thin longitudinal fiber muscles (some branched) along the anterior two thirds of the thorax; no
transverse muscle fibers; more than 30 tentacles of three orders forming one circle; pharynx with 10 to 12 rows of
stigmata with 13 to 15 stigmata in each half row; bilobed anus at the level of the fourth or fifth row of stigmata;
posterior abdomen not very elongated, oval, and joined to the abdomen by a narrow neck; numerous (> 30) testicular
follicles; ovary with about 15 oocytes at about the ninth or tenth row of stigmata in the thorax; large number of
embryos incubated in the atrial cavity in the right side of the thorax; larvae oval with a 0.65 mm long trunk, four clubshaped ectodermal ampullae in each side and three, linear and evenly spaced, adhesive papillae with thin stalks, two
clusters of ectodermal vesicles, one postero-ventral (around 15 vesicles) and another antero-dorsal (around eight vesicles)
between the ampullae and the oral siphon. This paper describes this new species and reports its occurrence in Brazil,
where it is most likely introduced. The hypothesis that it is introduced is based on 1) it was never found in previous
surveys, 2) in Brazil, it has a restricted and local distribution, 3) its type locality is near a major international port, and 4)
the genus, prior to this description, had never been found in the Atlantic Ocean. Considering the great abundance
found on the underside of natural boulders, it is imperative that S. peregrinus population growth be studied to evaluate
the possibility of rapid distribution expansion.
America, South
Western Atlantic warm temperate to tropical