Pseudobiceros evelinae ( Marcus 1950 )

Bahia, Juliana, Padula, Vinicius, Lavrado, Helena Passeri & Quiroga, Sigmer, 2014, Taxonomy of Cotylea (Platyhelminthes: Polycladida) from Cabo Frio, southeastern Brazil, with the description of a new species, Zootaxa 3873 (5), pp. 495-525 : 506

Pseudobiceros evelinae ( Marcus 1950)

( Fig. 9 )

Material examined. One juvenile specimen (MNRJ-PLAT 20, 2 x 2 mm), collected 20.04.2008. Two mature specimens (30 x 20 mm e 46 x 24 mm), the biggest as sagittal sections of reproductive structures (MNRJ-PLAT 21, 64 slides), collected 0 7.02.2009. One mature specimen (MNRJ-PLAT 22, 32 x 18 mm), collected 10.04.2009. One immature specimen (MNRJ-PLAT 23, 8 x 5 mm), collected 16.10.2009. All specimens preseved in ethanol 70% and collected at Praia das Conchas, Cabo Frio, Brasil (22°52'33.05"S, 41°58'39.27"W).

Distribution. Known only from Brazil. Originally described from Forte de Itaipú, Santos, São Paulo (type locality; Marcus 1950). Also reported from Extremoz, Rio Grande do Norte (Bahia et al. 2012) and from Cabo Frio, Rio de Janeiro (present study). Specimens collected under boulders and over the ascidian Symplegma rubra . This species was only collected at Praia das Conchas, where there is prey abundance.

Diagnosis. Body elongated with ruffled margin; background color wine red with three marginal bands; the innermost black, the median orange and the external thin and black. Pseudotentacular eyespots disposed in four dorsal and four ventral groups; male apparatus duplicated; seminal vesicle rounded.

Taxonomic remarks. We found both smaller and larger specimens (from 2 x 2 mm to 46 x 24 mm) than those described by Marcus (40 x 13 mm), but they presented one internal band that was not described by Marcus (1950). This can be related to specimen nutritional condition, as darker animals (better fed, or with different diet) present this band less defined related to dorsal coloration (personal observation).

We noted some differences between the specimens found in northeastern Brazil and those in Rio de Janeiro. The epidermis is thicker in southern animals (dorsal 50 µm, ventral 30 µm, against 37 µm in northern specimens), and muscular layers too (dorsal 40 µm, ventral 30 µm, against 14 µm in northern animals). Rhabdites in Cabo Frio’s specimens were present both dorsally and ventrally, but abundant only dorsally. As the specimens found in Cabo Frio were larger, ventral sucker measures such as diameter (1 mm) and distance from the anterior margin (18.5 mm) and female gonopore (4 mm) were also larger.

There are Pseudobiceros species in the Caribbean, Mediterranean and Indo-Pacific with the same “uniform background with different marginal bands” coloration pattern as P. evelinae , but none of them has dark red as background color ( Newman & Cannon 1997). It is suggested that these species should be studied together to clarify, with molecular tools, if they represent distinct taxa or variations of the same species.

Ecology. Pseudobiceros evelinae was observed associated with compound ascidians of the genus Symplegma ( Fig. 9 H). That was also observed both in the original description ( Marcus 1950) and posteriorly ( Marcus & Marcus 1951). We also observed specimens near ascidians in the family Didemnidae ( Fig. 9 I).

Figures

FIGURE 9. Pseudobiceros evelinae (MNRJ-PLAT 22) A. in vivo, dorsal view; B. ventral view; C. detail from the anterior region showing pseudotentacles and eyespots; D. detail from the anterior ventral region; E. detail from the ventral region showing pharynx, gonopores and sucker; F. sagittal section of male reproductive structures; G. sagital section of female reproductive structures; H. Pseudobiceros evelinae over Symplegma rubra; I. P. evelinae next to ascidians. as: ascidians; ce: cerebral eyespots; cg: cement glands; fg: female gonopore; it: main intestine; ma: male atrium; mg: male gonopore; pa: penis papilla; ph: pharynx; pt: pseudotentacles; pv: prostatic vesicle; st: stylet; su: sucker; sv: seminal vesicle; te: tentacular eyespots; ut: uterus; va: vagina.