Polybranchia schmekelae, Medrano & Krug & Gosliner & Kumar & Valdés, 2019

POLYBRANCHIA SCHMEKELAE View in CoL SP. NOV.

( FIGS 2, 3, 6, 8E –G, 18, 19)

Type material

Holotype: Bocas del Toro, Panama, 29 July 2015, one specimen 15-mm long, isolate MM064 ( LACM 3468 About LACM ).

Additional material examined

Curaçao, 24 August 2004, one specimen 8-mm long, isolate MM102 ( LACM 2004 About LACM – 98.1 About LACM ). Bocas del Toro , Panama, 28 July 2015, one specimen 13-mm long, isolate MM062 ( CPIC 01412 ); one specimen 14-mm long, isolate MM063 ( CPIC 01413 ) .

Description

External morphology: Colour pale to dark olive-green with specks of brown scattered over dorsum; specks disappear at lateral edges of body, covered with papillae. Rhinophores translucent olive-green with white papillae throughout. White pigmentation 01413; number unknown in specimen LACM 3468. Active tooth with two rows of ten blunt denticles (CPIC 01413) or two rows of 11 blunt denticles (CPIC 01412) on basal surface. Denticles small near base, larger toward distal portion, but decreasing in size at hooked cusp ( Fig. 19B, E).

Penis elongate, cylindrical, distally bearing numerous warty papillae and lacking a penial stylet in both specimens examined (LACM 2004–98.1; LACM 3468) ( Fig. 8E–G). Base wide, narrowing toward tip in specimen from Curaçao (LACM 2004–98.1); specimen from Panama (LACM 3468) with uniformly wide penis from base until last quarter of length, then narrowing towards tip ( Fig. 8G). Penis wavy, with distal loop, and blunt tip in Curaçao specimen (LACM 3468); erect with blunt tip in Panama specimen (LACM 2004–98.1) ( Fig. 8E–F).

forming small inverted triangle behind eyespots. Pericardium pale olive-green, lighter than rest of body, lacking brown specks ( Fig. 18). Large cerata translucent olive-green; dorso-medial surface with single minute black dot near distal margin and two enlarged papilla; ventral surface covered with many small white papillae ( Fig. 6F). Small cerata dark, olive-green, with 2–3 dark spots at tips. Ceratal peduncles with snowy white pigmentation in depression. Foot olive-green with scattered specks of brown and large white spots dispersed throughout.

Internal morphology: In a 14-mm long specimen from Panama (CPIC 01413), radula with 35 teeth: six in ascending limb, six distinct teeth and 23 teeth encased in tissue in descending limb ( Fig. 19A). In a 13-mm specimen from Panama (CPIC 01412), radula with 37 teeth: six in ascending limb, nine distinct teeth and 22 teeth encased in tissue in descending limb ( Fig. 19D). Ascus with four pre-radular teeth in specimen CPIC