Psednos

Stein, David L., 2012, A Review of the Snailfishes (Liparidae, Scorpaeniformes) of New Zealand, Including Descriptions of a New Genus and Sixteen New Species, Zootaxa 3588, pp. 1-54 : 33

Key to New Zealand Psednos species

1 Vertebrae more than 50 (≥ 11 abdominal vertebrae). Coronal pore absent........................................ 2

- Vertebrae 50 (≤ 10 abdominal vertebrae) or fewer. Coronal pore present or absent................................. 9

2 Peritoneum externally silvery when viewed at an angle. Gill opening ~9% SL, mandible to abdomen end ~44% SL............................................................................................. P. argyrogaster n. sp.

- Peritoneum black or dark when viewed at an angle, not silvery. Gill opening 7% SL or less, mandible to abdomen end less than 37% SL............................................................................................. 3

3 Posterior corner of lower jaw with two spines ( Fig. 28 ). Pectoral symphysis to abdomen end ~120% HL. Preanal fin length 190% HL, anus to anal fin length 116% HL................................................. P. cryptocaeca n. sp.

- Posterior corner of lower jaw with sharply angled retroarticular, anterior blunt spine absent. Pectoral symphysis to abdomen end about or less than 115% HL. Preanal fin length less than 170% HL, anus to anal fin length less than 100% HL........ 4

4 Distance mabd about 187% HL, pabd about 115%............................................ P. longiventris n. sp.

- Distance mabd less than 165% HL, pabd less than 107% HL.................................................. 5

5 Angle of mouth cleft about 30 degrees or less. Spinal hump prominent. Orbit greater than 30% HL.................... 6

- Angle of mouth cleft 50–60 degrees, distinctly more than 30 degrees. Spinal hump prominent or moderate. Orbit less than 30% HL................................................................................................. 8

6 Vertebrae 53, dorsal fin rays 45, pectoral fin rays 13, snout to anus distance 25% SL, anus to anal fin distance 65% HL, predorsal fin length 100% HL, preanal fin length 130% HL........................................... P. struthersi n. sp.

- Vertebrae 59, dorsal fin rays 49–53, pectoral fin rays 16–17, snout to anus distance 20% SL, anus to anal fin distance greater than 85% HL, preanal fin length greater than 155% HL, predorsal length 125% HL................................. 7

7 Dorsal fin rays 53, dorsal fin origin between vertebrae 4–5. Upper jaw about 50% HL, snout 17% HL.... P. c h a t h a m i n. sp.

- Dorsal fin rays 50, dorsal fin origin between vertebrae 7–8. Upper jaw about 40% HL, snout 27% HL..................................................................................................... P. platyoperculosus n. sp.

8 Dorsal fin insertion between vertebrae 5–6. First three neural spines much thicker than those posteriorly. Mouth angle 60 degrees. First three or four vertebrae forming a strong spinal curve reflected in a prominent hump, its posterior margin forming abrupt angle with body taper................................................................. P. nemnezi n. sp.

- Dorsal fin origin between vertebrae 7–8. First four neural spines thicker, spines 3 and 4 forked. Mouth angle 50 degrees. Dorsal hump moderate, its posterior margin blending smoothly into taper of body....................... P. sp. NMNZ 25760

9 Mouth small, upper jaw 26% HL. Premaxillary teeth tiny (visible only at 50x magnification), forming band near symphysis 3 or fewer teeth wide. V 49 ............................................................... P. microstomus n. sp.

- Mouth large, upper jaw more than 40% HL. Premaxillary teeth small, visible at much less than 50x magnification. Vertebrae fewer than 49....................................................................................... 10

10 Gill rakers paired, with parallel rows of spinules. Upper jaw about 60% HL. V ~42, P 14.................................................................................................. Psednos sp. 2 Chernova and Stein 2002

- Gill rakers mostly alternating, spinules irregularly arranged. Upper jaw about 50% HL. V 40, P unknown..................................................................................... Psednos sp. 3 Chernova and Stein 2002

Figures

FIGURE 28. Psednos cryptocaeca n. sp. Holotype. NMNZ P. 031114, 96 mm SL. A. lateral view. B. lateral view of preserved specimen. (Photo by C. Struthers, Te Papa)