Phrikoceros mopsus ( Marcus 1952 )

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 : 499-500

Phrikoceros mopsus ( Marcus 1952)

( Fig. 3 )

Material examined. One specimen (MNRJ-PLAT 25, 19 x 15 mm) collected 27.10.2007 at Ilha do Papagaio, Cabo Frio, Brazil (22°53'45.43"S, 41°59'5.54"W). One specimen (MNRJ-PLAT 26, 21 x 17 mm) collected 28.10.2007. One specimen (MNRJ-PLAT 27, 13 x 13 mm) collected 0 8.12.2007. One specimen (MNRJ-PLAT 28, 9 x 5 mm) collected 20.04.2008. Two specimens (MNRJ-PLAT 29, 10 x 8 mm; 24 x 19 mm) collected 21.04.2008. One specimen (MNRJ-PLAT 32, 30 x 23 mm) as sagittal sections of reproductive structures (41 slides) collected 30.08.2008. Vouchers 26 to 29 and 32 collected at Praia das Conchas, Cabo Frio, Brazil (22°52'33.05"S, 41°58'39.27"W). Two specimens (MNRJ-PLAT 30, 15 x 13 mm, 10 x 6 mm). Two specimens (MNRJ-PLAT 31, 26 x 21 mm; 18 x 17 mm), the bigger as sagittal sections of the reproductive structures (23 slides). Vouchers 30 and 31 collected 18.05.2008 at Canal de Itajuru, Cabo Frio, Brazil (22º53’11’’S, 42º00’08’’W). All especimens or especimens parts preserved in ethanol 70%.

Distribution. This species was described from Ilha de São Sebastião, São Paulo State, southeastern Brazil (type locality; Marcus 1952). It was also recorded from Antigua, Curaçao ( Marcus & Marcus 1968), Barbuda, Colombia ( Quiroga et al. 2004a) and Argentina ( Brusa et al. 2009; Bulnes et al. 2011). Also it was recently reported from Northeastern Brazil (Bahia et al. 2012), locality between its geographic distribution extremes. Our specimens of Phrikoceros mopsus were collected at rocky shores, under boulders with great amounts of ascidians, sponges and other marine invertebrates, and also at the sublittoral at Ilha do Papagaio where there are gorgonians and boulders reefs.

Diagnosis. Body oval and elongated, margin deeply ruffled. Dorsally, reticulated mottled pattern with white tiny spots. Median line darker than the rest of the body, margin with thin dark line. Four groups of pseudotentacular eyespots located dorsally and four ventrally. Opening of main intestine located at the anterior half of the body.

Taxonomic remarks. Our specimens characteristcs agree with those described by Marcus (1952). Differences we noticed were variations in color, problably due to nutritional condition or age ( Fig. 4 ), and number of eyespots and measures, probably due to size of specimens. The flatworms found at Cabo Frio were larger than those of Norheastern Brazil (Bahia et al. 2012) but smaller than those of Argentina ( Brusa et al. 2009). There could be a relation of specimen size and water temperature or nutrient availability, but ecological studies should be undertaken to answer this question.

Figures

FIGURE 3. Phrikoceros mopsus (MNRJ-PLAT 32). A. in vivo; B. ventral view; C. detail from the anterior region showing pseudotentacles, cerebral and tentacular eyespots; D. detail from the pseudotentacles showing pseudotentacular eyespots; E. sagittal section of male and female reproductive structures (MNRJ-PLAT 31). 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; vd: vas deferens.

FIGURE 4. Color variation in Phrikoceros mopsus. A. MNRJ-PLAT 32; B. MNRJ-PLAT 27; C. MNRJ-PLAT 28; D. MNRJ- PLAT 31; E. MNRJ-PLAT 30; F. MNRJ-PLAT 25; G. MNRJ-PLAT 29; H. MNRJ-PLAT 28 in situ.