Kirkegaardia brisae sp. nov.

urn:lsid:zoobank.org:act: F91EA4FC-D190-405B-82B7- 675FF65BBDCD

Fig 4

Material examined. BRAZIL: Campos Basin – Holotype – -19.87490556˚S -39.81891667˚W, 41 m, 16/07/11, (MNRJP-002974); Paratypes – -19.87490556˚S -39.81891667˚W, 41 m, tree ind., 16/07/11, (MNRJP-002975); -19.69275556˚S -39.52159444˚W, 48 m, 20 ind., 12/12/10, (MNRJP-002976); -19.87652222˚S -39.81822222˚W, 35 m, six ind., 16/12/10, (MNRJP-002977); -19.83260556˚S -39.87056111˚W, 37 m, one ind., 15/12/10, (MNRJP-002978); -19.69027500˚S -39.52233889˚W, 44 m, 17 ind., 13/07/11, (MNRJP-002979); -19.58430556˚S -39.64418333˚W, 41 m, one ind., 14/07/11, (MNRJP-002980); -19.95898889˚S -39.89250278˚W, 46 m, one ind., 17/07/ 11, (MNRJP-002981); -19.62828611˚S -39.59208889˚W, 35 m, one ind., 15/07/11, (MNRJP-002982); -19.92933056˚S -39.76148611˚W, 43 m, one ind., 16/07/11, (MNRJP-002983); -19.83788611˚S -39.66978611˚W, 48 m, one ind., 15/07/11, (MNRJP-002984); -19.76963611˚S -39.58217778˚W, 44 m, one ind., 14/07/11, (MNRJP-002985); -19.78693056˚S -39.92095000˚W, 14 m, seven ind., 16/07/11, (MNRJP-002986); -19.91400833˚S -39.94639167˚W, 32 m, one ind., 16/07/11, (MNRJP-002987); -19.76538611˚S -39.50715000˚W, 121 m, one ind., 15/01/12, (MNRJP-002988); -19.76025000˚S -39.59519167˚W, 352 m, one ind., 28/06/13, (MNRJP-002989).

Diagnosis. Thoracic parapodia elevated above dorsal surface producing a groove between notopodia. Two or three rings on anterior region of peristomium. Pre-pygidial region slightly expanded with pygidium formed by an enlarged ventral lobe.

Description. Complete holotype with 90 setigers, 2.8 mm long, thoracic region 0.08 mm wide, abdominal region 0.12 mm wide. Prostomium large conical (Fig 4A); eyes absent. Peristomium large with two or three rings visible with optical microscope (Fig 4A). Dorsal tentacles on posterior margin of peristomium (Fig 4A). First pair of branchiae postero-lateral to the tentacles, second pair of branchiae inserted on setiger one dorsal to notosetae (Fig 4A); branchiae absent on abdominal segments. Thoracic region slightly expanded, with 8–10 setigers; dorsal thoracic groove visible in light microscope (Fig 4A). Abdominal segments wider than long (Fig 4B). Parapodia with poorly developed lobes, difficult to see under optical microscope. Thoracic parapodia with 3–7 simple capillaries per segment. Posterior abdominal parapodia with 3–5 noto- and denticulated neurosetae per fascicle (Fig 4C and 4D). Denticulated neurosetae appear first between the abdominal setigers 10 and 24. Pre-pygidial region slightly expanded (Fig 4E). Pygidium formed by an enlarged ventral lobe (Fig 4E).

Remarks. Kirkegaardia brisae sp. nov. is similar to K. cryptica (Blake, 1996) [2]. These species have a conical and wide prostomium, tentacles in the posterior portion of the peristomium, the first pair of branchiae postero-lateral to the tentacles and noto- and neurosetae denticulate. K. brisae sp. nov. differs from K. cryptica in that it has three rings with the first two short and narrow and the third longer than the two short ones instead of being smooth and without annulations as in K. cryptica . Kirkegaardia brisae sp. nov. is similar to K. annulosa (Hartman, 1965) [37] due to the location of peristomial rings right after the prostomium, but K. annulosa has a peristomial and thoracic crest, while K. brisae sp. nov. has no crest. K. brisae sp. nov. is also similar to K. baptisteae (Blake, 1991) [27] in that they both have an expanded pre-pygidial region, but the latter differs in having a pygidium formed by a narrow terminal lobe. In contrast, K. brisae sp. nov. has a terminal lobe expanded distally. For these characteristics, the species was considered as new to science.

Etymology. This species is named in honor of Mrs. Suzanne Marie Thérèse Bris in recognition of her encouragement to young scientists in the study of polychaetes.