Azygopus Norman 1926
Creators: name: Munroe, Thomas A.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Pleuronectiformes
Pleuronectidae
Azygopus

description: Azygopus Norman 1926
(After Norman, 1926; 1934; present study)
Description: Dextral asymmetry. Body ovate to relatively elongate, laterally compressed. Eyes nearly entirely contiguous, upper eye close to dorsal margin of head; some areas on snout and entire upper surfaces of eyes with dense patches of scales; blind-side nasal organ nearer median line of head than that of ocular side; olfactory laminae in moderate number, radiating from fairly long central rachis. Mouth relatively small, its posterior extent not reaching beyond vertical through middle of lower eye; jaws subsymmetrical; teeth small, better developed on blind-side jaws; blind-side jaws with several bands of small, movable, pointed, teeth, not enlarged anteriorly; vomer toothless. Gillrakers short, in moderate number (3–6 on upper limb, 8–14 on lower limb; total gillrakers 11–20); lower pharyngeals moderately broad, curved, approximated anteriorly, each with 3–4 irregular rows of teeth; branchial septum entire. Dorsal-fin origin on blind side of head at a point dorsal to nostrils and just anterior to anterior margin of upper eye; first dorsal-fin ray elongate, detached from remainder of fin; most dorsal-fin rays simple, without scales; a low scaly sheath covering basal part of fin on ocular side; dorsal-fin rays 95–114. Supracranial proximal dorsal-fin pterygiophores usually 7–9 (6–10); a single proximal pterygiophore associated with first neural spine; usually 4–5 (1–7) proximal pterygiophores inserted into first interneural space. Anal fin similar in size and posterior extent as that of dorsal fin; ventral tip of first interhaemal spine not projecting anteriorly to anal-fin origin; anal-fin rays 78–97; usually 12–14 (9–15) anal-fin proximal ptergygiophores inserted anterior to first haemal spine. Pectorals unequal in size, that of ocular side longer; middle rays branched; ocularside pectoral-fin rays usually 10–11 (6–12), blind-side pectoral-fin rays usually 6–7 (4–10). Both pelvic fins developed; ocular-side pelvic-fin base elongate, usually with 9–11 rays (6–12), free from anal fin; blind-side pelvic fin with 5–6 rays (rarely 4), base of blind-side pelvic fin very short compared with ocular-side counterpart. Caudalfin rays usually 18 (rarely 17 or 19), 10–12 middle rays branched; caudal peduncle very short. Abdominal vertebrae usually 10–11, rarely 9 (3 without hemapophyses and 7–8 with hemapophyses); total vertebrae 45–49. Scales rather small, adherent, imbricated, ctenoid on both sides of body. Lateral line with slight low curve dorsal to pectoral fin; no supratemporal branch; lateral-line scales 88–113. Anus deflected slightly to blind side of body, just anterior to anal-fin origin; intestine short. Genital pore on right side of body.
description: Published as part of Munroe, Thomas A., 2012, The spotted flounder, Azygopus flemingi Nielsen 1961 (Pisces: Pleuronectiformes: Rhombosoleidae), from deep waters off New Zealand: a second valid species of Azygopus Norman 1926, with notes on distribution, size, maturity, and ecology, pp. 1-33 in Zootaxa 3297 on page 4, DOI: 10.5281/zenodo.215502