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

POLYBRANCHIA JANNAE View in CoL SP. NOV.

( FIGS 2, 3, 6A, 11, 12)

Type material

Holotype: Yabob , Madang Province, Papua New Guinea, 5 December 2012, 10-mm long, isolate MM069 ( CASIZ 191544 ).

Additional material examined

Arthur’s Place , Mabini (Calumpan Peninsula), Batangas, Luzon Island, Philippines, 20 April 2008, one specimen, isolate MM066 ( CASIZ 177697 ) .

Description

External morphology: Colour typically translucent golden yellow to light brown with numerous small orange and purple spots throughout dorsum ( Fig. 11). Rhinophores translucent with several white papillae. Small orange and purple patches extend on to rhinophores. Pericardium pigmented with snowy white. Cerata fan-shaped with a single white to yellow large papilla on dorsal-medial surface; small papillae with white tips present on both dorsal and ventral sides. Many orange and purple spots scattered throughout; deep purple line near base extends medially and vertically to half each ceras length and abruptly changes to a red-orange extending to distal end, without reaching white tipped margin ( Fig. 6A). Unique white or yellow lines resembling cobweb present on entire surface of cerata ( Fig. 6A).

Internal morphology: In a 10-mm long specimen from Papua New Guinea (CASIZ 191544), radulae with 24 teeth: four in ascending limb, four distinct teeth and 16 teeth encased in tissue in descending limb ( Fig. 12A). In specimen from the Philippines (CASIZ 177697), radula with 29 teeth: six in ascending limb, five distinct teeth and 18 teeth encased in tissue in descending limb ( Fig. 12D). Additional teeth encased in ascus in both specimens ( Fig. 12C, F); number unknown. Leading tooth with two rows of 12 blunt denticles on basal surface in Papua New Guinea specimen (CASIZ 191544), enlarged near base and decrease in size toward hooked cusp ( Fig 12B), and with two rows of 14 blunt denticles on convex ventral surface in Philippines specimen (CASIZ 177697). Denticles small near base; enlarged as they ascend toward cusp and reduced in size at hooked cusp ( Fig. 12E).

Penial morphology not observed; both specimens were castrated by parasitic copepods.