Psednos

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