Description of two new genera, Santelmoa and Bentartia and two new species of Zoarcidae (Teleostei, Perciformes) from the Southern Ocean

Abstract

Two new genera of lycodine zoarcid fish, Santelmoa and Bentartia, and two new species, Santelmoa carmenae and Bentartia cinerea, are described from 13 specimens collected from the Gerlache Strait, Southern Ocean, at 1,056-m depth. Santelmoa can be distinguished from all other lycodine genera by the combination of the following characters: anterior portion of frontals fused; scapular foramen open; ceratohyal–epihyal articulation interdigitating; cranium narrowed; supratemporal commissure and occipital pores absent; intercalar reaching the prootic; parasphenoid wing well developed; palatal arch well developed; posterior hyomandibular ramus short; post-temporal ventral ramus well developed; six branchiostegal rays; vertebrae asymmetrical; pelvic fin rays ensheathed; scales, lateral line, pyloric caeca, palatine and vomerine teeth present. Bentartia differs from the remaining lycodine genera by the following combination of characters: basioccipital and exoccipitals fused; supraoccipital–exoccipital articulation broadly contacting; ceratohyal–epihyal articulation interdigitating; post-temporal ventral ramus weak; two posterior nasal pores; cranium narrowed; supratemporal commissure and occipital pores absent; intercalar set posteriorly; palatal arch well developed; posterior hyomandibular ramus not elongate; parasphenoid wing high; six branchiostegal rays; vertebrae asymmetrical; pelvic fin rays ensheathed; scales, lateral line, pyloric caeca, palatine and vomerine teeth present. The relationships of the two new genera are discussed.

Appendix 1

The monotypic Lycozoarces (Lycozoarcinae), primitive sister group of all other zoarcids (Anderson 1994), was designed as outgroup taxa. TS numbers used here are those assigned to each character by Anderson (1994), with the following additions: frontal fusion (TS 23) could be considered as multi-state (0, 1, 2); a new TS, number 77, is added. TS3, squamation: present (0), absent (1); TS4, condition of flesh: firm (0), gelatinous (1); TS5, lateral line: present (0), absent (1); TS9, lower lip attachment: adnate (0), free (1); TS10, lip grooves: absent (0), present (1); TS11, elongate facial papillae: absent (0), present (1); TS12, oral valve reduction: free edge extends to vomer (0), free edge well before vomer and valve laterally constricted (1), absent (2); TS14, chin pad: absent (0), present (1); TS16, pseudobranch filaments: 6–13 (0), 0–5 (1); TS17, pyloric caeca state: present (0), absent (1); TS18, pyloric caeca development: nubbins (0), elongate (1); TS20, parasphenoid wing height: high (0), reduced (1); TS21, frontal corner: squared off (0), tapering (1); TS22, frontal ramus: long (0), shortened (1); TS23, frontal fusion: separate (0), fused anteriorly (1), fused completely (2); TS24, cranium width: wide (0), narrowed (1); TS25, frontal–parasphenoid articulation: not separated by pterosphenoid (0), separated by pterosphenoid (1); TS26, sphenotic–parietal articulation: separated by frontals (0), in contact (1); TS27, parietal–parietal articulation: separated from midline (0), in contact (1); TS29, supraoccipital–exoccipital articulation: narrowly contacting or excluded by epioccipitals (0), broadly contacting (1); TS33, suborbital bone configuration: circular pattern (0), L-shaped pattern (1); TS35, preopercular and mandibular canals: continuous (0), separated (1); TS37, supratemporal commissure and occipital pores: present (0), absent (1); TS40, posterior nasal pore development: single (0), double (1); TS44, incisiform dentition: absent (0), present (1); TS45, palatine teeth: present (0), absent (1); TS46, vomerine teeth: present (0), absent (1); TS47, branchiostegal membrane: free of isthmus (0), attached to isthmus, with gill slit extending to or below the ventral edge of the pectoral fin base (1), attached to isthmus, with gill slit extending to about mid-pectoral base (2), gill slit above pectoral base, pore like (3); TS48, palatopterygoid series development: well developed (0), reduced (1); TS49, posterior ramus of hyomandibula: short (0), elongate (1); TS50, ceratohyal–epihyal articulation: smooth (0), interdigitating (1); TS51, branchiostegal ray reduction: rays 6 (0), rays 4–5 (1); TS52, branchiostegal ray addition: rays 6 (0), rays 7–8 (1); TS56, postorbital canal passage: through lateral extrascapulars, post-temporal and supracleithrum (0), through lateral extrascapulars only (1); TS57, post-temporal ventral ramus: well developed (0), weak or absent (1); TS59, scapular foramen: enclosed by bone (0), open (1); TS63, pectoral fin: well developed (0), reduced (1), minute, nub-like (2), absent (3); TS64, number of pelvic fin rays: 2–3 (0), absent (1); TS65, pelvic fin membranes: rays joined, ensheathed (0), rays exserted (1); TS67, number of vertebrae: 58–71 (0); 72–105 (1), 109–134 (2), 134–150 (3); TS69, advanced dorsal fin origin: first pterygiophore associated with vertebrae 1 or greater (0), first pterygiophore anterior to first vertebrae (1); TS74, number of epurals: 2 (0), 1 (1), absent (2); TS75, number of epural caudal fin rays: 3 (0); 1–2 (1); TS76, number of caudal fin rays: 13–15 (0), 9–12 (1), less than 9 (2); TS77, basioccipital–exoccipital fusion: separate (0), fused (1).