Thaumatoconcha porosa Kornicker 1985

Thaumatoconcha porosa Komicker, 1985, 3716 m, Indian Ocean

Second Antenna: Protopodite with or without small areas of medial spines; three species of Danielopolina with bristle on posteroventral corner [unique among the Myodocopa]. Endopodite: Thaumatoconcha: 1st joint with 3 bristles (1 ventral, 2 dorsal); 2nd joint with 5 bristles (1 lateral, 4 terminal); 3rd joint of female with 2 or 3 bristles, of male with sclerotized clasper. Danielopolina: 1st joint with no ventral and 2 dorsal bristles; 2nd joint of female with none or 1 lateral bristle and 3 terminal bristles, except for 4 terminal bristles on D. carolynae; 2nd joint of male with none or 1 lateral bristle and 4 terminal bristles; 3rd joint of female with 1 bristle, of male with sclerotized clasper (clasper with spines and 2 minute terminal bristles on some species). Thaumatocypris: 1st joint with 1 ventral and 2 dorsal bristles; 2nd joint with 1 short dorsal bristle and 4 long terminal filament-like bristles (unlike Thaumatoconcha and Danielopolina, the male Thaumatocypris is without a clasper). Exopodite with 8 or 9 joints with 1st joint divided into long proximal and short distal parts; 1 st joint bare, except for Danielopolina carolynae which bears a long bristle; 9th joint with 2 bristles, except for Thaumatoconcha radiata which has 2 or 3.

Mandible (endopodite): 1st joint with 1 dorsal bristle, except for Thaumatoconcha polythrix which has 4–6, and Danielopolina orghidani which has none; 2nd joint with 3 or 4 ventral and 2 or 3 dorsal bristles. 3rd joint with 6 or 7 bristles including very long claw-like bristle.

Maxilla (endopodite): 1st joint: Thaumatoconcha with 5–7 anterior bristles and 2 or 3 posterior bristles; Thaumatocypris with 4 or 5 anterior bristles and 2 or 3 posterior bristles; Danielopolina with 3 or 4 anterior bristles and 2–4 posterior bristles. 2nd joint: Thaumatoconcha with 8 or 9 bristles; Thaumatocypris with 6 bristles; Danielopolina with 5–8 bristles.

Fifth Limb (exopodite): 1st joint with 1 dorsal bristle and 5–11 ventral bristles. 2nd joint: Thaumatoconcha with 2 or 3 midventral bristles and no ventral terminal bristle; Thaumatocypris with 2 midventral bristles and no ventral terminal bristle; Danielopolina with 2 midventral and none or 1 ventral terminal bristle. 3rd joint: Thaumatoconcha with 2 bristles; Thaumatocypris with 3 bristles; Danielopolina with 2 or 3 bristles.

Sixth Limb: Exopodite: 1st and 2nd joints fused: Thaumatoconcha with 3 or 4 bristles (2 or 3 midventral, 1 dorsal); Thaumatocypris with 3 bristles (2 midventral, 1 dorsal); Danielopolina with 2 or 3 midventral bristles (Danielopolina carolynae also with 1 terminal ventral bristle), and none or 1 dorsal bristle. 3rd joint: Thaumatoconcha with 2 bristles; Thaumatocypris with 3 bristles; Danielopolina with 2 bristles, except for of D. bahamensis which has only 1. Endopodite: Thaumatoconcha with 3 plumose bristles; Thaumatocypris with 1 long bare bristle and 1 minute spine; Danielopolina with 2 bristles.

Seventh Limb: Elongate with 2 terminal bristles.

Furca: With anterior and ventral edges forming right-angle; claws on anterior margin articulated, those on ventral margin nonarticulated. Thaumatoconcha with 2 articulated anterior claws and 6 nonarticulated ventral claws; Thaumatocypris with 2 articulated anterior claws and 6 or 7 nonarticulated ventral claws; Danielopolina with 1–4 articulated anterior claws and 3–6 nonarticulated ventral claws (total number of claws 4–8).

Bellonci Organ: Thaumatoconcha: elongate with rounded tip. Thaumatocypris: T. echinata with short cone-like organ in female (Poulsen, 1969:12), but not discernible in male (Rudjakov, 1993:307). Danielopolina: elongate with rounded tip in some species (generally diaphanous), absent in others.

Lips: Distal edge of upper lip with 4 spine-like processes oriented posteriorly. Lower lip with lateral sclerotized triangular process oriented anteriorly on each side of mouth.

Anterior of Body: A sclerotized triangular process present on each side of body dorsal to upper lip.

Posterior of Body: Appearing wrinkled and segmented.

Genitalia: Female genitalia generally not discernible. Single male genitalia consisting of 2 parts present only on left side of body: a styliform posterior process with several terminal hairs, and a longer stouter anterior process with sclerotized tip. The anterior and posterior parts appear to move independently of each other so that their positions are reversed on some specimens; also, the limbs appear to be capable of turning 180 degrees so that the tip of the long sclerotized part points anteriorly on some specimens and posteriorly on others. Thaumatoconcha: the sclerotized tip of the anterior part varies considerably among species (see Komicker and Sohn, 1976, fig. 18). Adjacent to the tip is a broad transparent lobe, except in T. porosa, in which the lobe is absent (Komicker, 1985, fig. 3g,h). Thaumatocypris: the anterior part consists of a curved distal part with broadly rounded tip, and a pointed sclerotized process just proximal to it (Rudjakov, 1993, fig. 43f). Danielopolina: The anterior part consists of a bare pointed sclerotized tip without an adjacent transparent lobe and is similar to the copulatory organ of Thaumatoconcha porosa. The adult male is unknown for D. carolynae, the type species of the genus.

Heart: Probably always present but not clearly visible in many species.