Pseudoceros rawlinsonae var. galaxy, Cuadrado & Rodríguez & Moro & Grande & Noreña, 2021

Cuadrado, Daniel, Rodríguez, Jorge, Moro, Leopoldo, Grande, Cristina & Noreña, Carolina, 2021, Polycladida (Platyhelminthes, Rhabditophora) from Cape Verde and related regions of Macaronesia, European Journal of Taxonomy 736, pp. 1-43 : 18-19

Pseudoceros rawlinsonae var. galaxy var. nov.

Figs 1C , 3 E–I

Etymology

The name ‘galaxy’ comes from the pattern of the small white spots on the dorsal surface, which resemble a star galaxy.

Material examined (2 specs)

Holotype CAPE VERDE • S„o Vicente Island , Baía das Gatas ; 16°54′09.33″ N, 24°54′25.25″ W ( Fig. 1C V 2 ); 5 May 2017; Leopoldo Moro leg.; MNCN 4.01/2729 to 2798 (70 slides). One sagittally sectioned specimen stained with AZAN.

Additional material

CAPE VERDE • 1 spec.; same collection data as for holotype; RCCN .

Description

BODY. Shape oval. Length 2.3 cm. Smooth dorsal surface. Background color dark to velvety brown with white dots and spots that draw a longitudinal line along the body axis. One thin bright yellow external line and another internal and black line surround the entire body margin. The yellow one is interrupted at the pseudotentacles level ( Fig. 3 E–F). Marginal body edges lined with transversal whitish elongated drops ( Fig. 3F ). Ventral coloration dark grey to black. Ventral sucker in the middle of the body ( Fig. 3G ). Pseudotentacles constitute two simple folds that present each of them a small cluster of tentacular eyes in their margin. Round cluster of cerebral eyes present and surrounded by a spot of white pigment. Pharynx ruffled, butterfly-shaped and located at the anterior third of the body. Oral pore, female and male gonopore close to each other and located at the anterior end ( Fig. 3G ). Male and female genital pores located after the pharynx in the anterior half of the body ( Fig. 3 H–I).

MALE REPRODUCTIVE SYSTEM. Male genital pore between the posterior lobes of the ruffled pharynx. Male copulatory organ dorso-ventrally orientated consists in a prostatic vesicle and a very muscular seminal vesicle, as well as a penis papilla armed with a stylet ( Fig. 3 H–I). Vasa deferentia open separately into the seminal vesicle. Seminal vesicle rounded, frontally oriented and lined with a thick muscular wall. Prostatic vesicle rounded, muscular and smaller than the seminal vesicle. Sperm duct muscular and long, extends frontally to join the prostatic duct inside the proximal end of the conical stylet. The short ejaculatory duct appears surrounded by the stylet cone and the penis sheath. The male atrium is wide and tetra-folding (fork-like) as characteristic of the genus ( Fig. 3I ).

FEMALE REPRODUCTIVE SYSTEM. With a short muscular vagina, backwards oriented and surrounded by cement glands.

Remarks

The genus Pseudoceros comprises approximately 89 species with similar copulatory organs, but bright and unique coloration patterns. However, within these patterns some taxa share evident similarities. Pseudoceros rawlinsonae var. galaxy shares with P. bicolor Verril, 1902 , P. mororum and P. rawlinsonae Bolaños, Quiroga & Litvaitis, 2007 the brown background and one whitish, broad marginal band, but in P. bicolor the marginal band is wide with inner waves ( Litvaitis et al. 2010: fig. 4a–i); P. rawlinsonae shows, in addition to the wide band, a thin orange line ( Litvaitis et al. 2010: fig. 4j–p); in P. mororum the whitish band is interrupted and drop-shaped and additionally, two orange marginal stripes border the entire body ( Cuadrado et al. 2017: fig. 6a–b); finally, the Cape Verdean species shows, together with the drop-shaped white band, two black and orange thin lines ( Fig. 3 E–F).

Although the four previously mentioned species can be clearly differentiated due to their coloration, this is not the case in the molecular analysis (Fig. 8). In both the Bayesian and Maximum Likelihood analyses, individuals from Cape Verde appear closely related to P. rawlinsonae , so much so that the separation of both populations (the Cape Verdean population and the Caribbean population) is only possible at the level of variety, not of species. Therefore, we determined the individuals from Cape Verde as a variety within the species P. rawlinsonae .

Nonetheless, we want to emphasize that the decision to maintain this population (organisms) as a ‘variety’ of the species P. rawlinsonae is the sole and exclusive responsibility of the authors. We are aware that ‘variety’ is not a taxonomic category (according to ICZN) and that therefore it will remain a non-existent species until molecular analyses allow us to consider it as such.

Figures

Fig. 1. Location of sampling points, distribution of the Macaronesian archipelagos and limitation of regions: Lauri-Macaronesia or Lusitanian Macaronesia (white); Central Macaronesia or Eumacaronesia (bordeaux) and Great Macaronesia (green). Abbreviations:A1 = San Miguel Island, Azores; C1 = Pasito Blanco, Gran Canaria, Canary Islands; C2 = Tenerife, Canary Islands; C3 = Garachico, Tenerife, Canary Islands; C4 = Amarilla Golf, Tenerife, Canary Islands; CV1 = Astillero Mindelo, S„o Vicente Island, Cape Verde; CV2 = Bahía das Gatas, S„o Vicente Island, Cape Verde; CV3 = Calheta Funda, Sal Island, Cape Verde; M1 = Ifni, South Morocco; M2 = Agadir, South Morocco.

Fig. 3. A–D. Prostheceraeus crisostomum sp. nov. (MNCN 4.01/2684 to 2698). A. Whole live animal, dorsal view. B. Anterior region with cerebral eyes cluster and tentacles (black arrows). C. Histological section of the reproductive system stained with AZAN. D. Histological section of the whole animal stained with AZAN and sagittal reconstruction. – E–I. Pseudoceros rawlinsonae var. galaxy (MNCN 4.01/2729 to 2798). E. Whole live animal, dorsal view. F. Anterior region with eyes cluster and tentacles (white arrows). G. Whole live animal, ventral view. H. Histological sagittal section of male and female copulatory organ. I. Sagittal reconstruction of the reproductive system. Abbreviations: see Material and methods.

Fig. 2. Marcusia alba sp. nov. (MNCN 4.01/2620 to 2683).A. Whole live animal, dorsal view.B. Anterior region with cerebral eyes cluster and pseudotentacles (white arrows). C. Histological section of the male copulatory organ stained with AZAN. D. Histological section of the female copulatory organ stained with AZAN. E. Sagittal reconstruction of the reproduction system. Abbreviations: see Material and methods.