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

POLYBRANCHIA JENSENAE View in CoL SP. NOV.

( FIGS 2, 3, 6A–C, 8, 13, 14)

Type material

Holotype: West Philippine Sea coast, Calatagan, Batangas Province, Luzon Island, Philippines, 13–15 May 2014, live animal 51 mm in length, 25-mm long preserved, isolate MM121 ( NMP 041295 View Materials ).

Additional material examined

Kahului Harbor , Maui , Hawaiian Islands , 20 June 2011, one specimen, isolate JG028 ( CPIC 00379 ), 10-mm long; one specimen, isolate JG029 ( CPIC 00376 ), 10-mm long; one specimen, isolate JG030 ( CPIC 00376 ), 9-mm long. Anini Beach , Kaua‘i, Hawaiian Islands, 12 July 2016, one specimen, 9-mm long, isolate MM029 ( CPIC 01778 ) . Hekili Point , Maui, Hawaiian Islands, 21 June 2016, one specimen, 19-mm long when alive, 6-mm long preserved, isolate MM030 ( CPIC 01649 ) . Mama’s Fish House , Maui, Hawaiian Islands, 25 June 2016, one specimen, 11-mm long, isolate MM031 ( CPIC 01650 ) ; one specimen, 5-mm long, isolate MM032 ( CPIC 01651 ) ; one specimen, 3 mm-long, isolate MM033 ( CPIC 01652 ) . Verde Island Passage coast, Calatagan, Batangas, Luzon, Philippines, 9 May 2014, one specimen, 8 mm-long, isolate MM119 ( CASIZ 199267 ) ; 8 May 2014, one specimen, isolate MM118 ( CASIZ 199266 ) .

Description

External morphology: Colour translucent dark grey or completely translucent in smaller animals; small white papillae throughout body ( Fig. 13). Faded white patches may be present throughout dorsum. Rhinophores translucent with several white papillae; upper portion of dorsal rhinophores with thin, translucent dark grey or pale yellow medial line. Pericardium translucent grey with few white spots. Cerata fan-shaped with yellow or white pigment on the 2–3 larger papillae; overall translucent olive-green with white web-like network on dorsal surface. Ceratal peduncles with snowy white pigment in depression. Dark black patch, above peduncle depression ( Figs 6B–C, 13A, C, D). Small cerata pale yellow. Foot translucent grey with white spots, except for translucent and colourless animals in which foot is only with white spots.

Internal morphology: In a 9-mm long specimen from Maui, Hawaiian Islands (CPIC 00376), radula with 29 teeth: six in ascending limb, five distinct teeth and 18 teeth encased in tissue in descending limb ( Fig. 14A). In a 9-mm long specimen from Kaua‘i, Hawaiian Islands (CPIC 01778), radula with 38 teeth: six in ascending limb, five distinct teeth and 27 teeth encased in tissue in descending limb ( Fig. 14D). Additional teeth encased in ascus in specimen CPIC 00376 ( Fig. 14C); number unknown. Ascus with three pre-radular teeth in specimen CPIC 01778 ( Fig. 14F). Teeth shape variable; slightly slender in Kaua‘i specimen (CPIC 01778), with upper surface convex, more straight in specimen from Maui (CPIC 00376). Leading tooth with two rows of ten worn-down denticles on basal surface, increasing in size near base and decreasing at ‘hooked’ cusp ( Fig. 14B) in Maui specimen (CPIC 00376) and with two rows of 14 denticles on basal surface, increasing then decrease in size from base towards hooked cusp ( Fig. 14E) in Kaua‘i specimen (CPIC 01778).

Penis long, smooth and cylindrical in the Hawaiian Islands (CPIC 01778) and the Philippines’ specimens (CASIZ 199267) ( Fig. 8A, B). Penis of 8-mm long specimen from the Philippines (CASIZ 199267) bent at mid-length, tip coiled and blunt ( Fig. 8A). Penis of 9-mm long specimen from the Hawaiian Islands (CPIC 01778) erect and wide at base, mid-length varies in width and narrows toward the loosely coiled unarmed blunt tip ( Fig. 8B).