Sabatieria bitumen sp. nov. (Figure 6 and 7)

Description

Studied material: 6 males; 5 females.

Type material: Male holotype MNRJ 309; Female allotype MNRJ 310; Five male paratypes 54–58 NM LMZOO­UFPE; Four female paratypes 59–62 NM LMZOOUFPE.

Type locality: Campos Basin (Rio de Janeiro, Pernambuco, Brazil), found at 750 and 1650 meters depth in silt­clay sediments.

Measurements: see table 4.

HOLOTYPE PARATYPE ALLOTYPE PARATYPE ...... continued on the next page Etymology: The specific name bitumen means oleum. It is named in honour to the Brazilian Petroleum Company (PETROBRAS).

Male:

Cylindrical body. Punctated cuticle with transversal rows of dots and lateral differentiation of larger dots, easily visible on tail region. Attenuated head. Six inner labial setae, six outer labial setae and four cephalic setae. Buccal cavity is small and cup­shaped. Somatic setae short. Amphidial fovea spiral with two turns and a half and occupying 78% of the corresponding body diameter. Pharynx clavate gradually expanding towards the posterior end, but without distinct bulb. Cardia short and small. Nerve ring slender located at the middle of pharynx, anterior to secretory­excretory pore. Ventral gland between the terminal region of the pharynx and the beginning of the intestine. Reproductive system composed by two opposed and outstretched testes, the anterior on the left and the posterior one on the right of the intestine. Spicules curved and paired with distal part hook­like, proximal end with a septum almost up to ½ of the spicule. This median rib divides the spicule into dorsal and ventral halves. There are several glandular cells located around the spicules. Gubernaculum short with a narrow dorsal apophysis. The spermatozoa are elongated. Eight pore­shaped precloacal supplements and a precloacal setae are present. Tail conical and short with 3 caudal glands endimg in a spinneret. Two caudal setae.

Female:

Females similar to males. Amphidial fovea spiral with three turns occupying 66% of the corresponding body diameter. Buccal cavity cup­shaped. Pharynx cylindrical, gradually expanding towards the posterior end, but without distinct bulb. Cardia short and small. Nerve ring slender located at the middle of pharynx and anterior to secretory­excretory pore. Ventral gland between the end of pharynx and the beginning of intestine. Reproductive system didelphic­amphidelphic with ovaries outstretched and relatively short. Vulva at midbody, similar to S. spiculata (figure 2C). Tail conical and short. Three caudal glands ending in a spinneret and two terminal setae.

Diagnosis

This species is characterized by the presence of lateral differentiation with larger equally distributed dots in rows; head diameter 11–12 µm ɗ; hook­like projection in distal portion of spicule; 6–10 pore­like precloacal supplements.

Relationships

Sabatieria bitumen resembles S. conicauda Vitiello, 1970 in body and tail shape, as well as morphometric values and the De Man’s index. However, Sabatieria bitumen may be distinguished from S. conicauda in relation to spicule length ( S. conicauda = 36–37 µm and S. bitumen = 40–47 µm) and projection of the distal portion of it.

This new species resembles S. praedatrix de Man, 1907 and S. flecha Pastor de Ward, 2003 in the projection present in the distal half of the spicule, can be differenciated in the shape, arrow­like in S. praedatrix and S. flecha and hook­like S. bitumen . S. lepida Vitiello, 1976 has a triangular ventral projection in the distal part of spicules and S.bitumen has a hook­like projection. Moreover, tail is conical in S. bitumen and conico­cylindrical in S. praedatrx, S.lepida and S. flecha .