Pseudophycis Gunther 1862

Genus Pseudophycis Günther, 1862

Pseudophycis Günther, 1862: 350, type species: Lota breviuscula Richardson, 1846, by monotypy.

Austrophycis Ogilby, 1897: 90, type species: Austrophycis megalops Ogilby, 1897 (= P. breviuscula) by monotypy.

Physiculus (Pseudophycis) Whitley, 1956: 403, taxonomic decision.

Diagnosis. Morid fishes with an elongate body. Luminescent organs absent. Snout broadly rounded in dorsal view, not projecting greatly beyond mouth, length about equal to interorbital width. Eye diameter much less than postorbital length. Each jaw with broad band of small, depressible, caniniform teeth of uniform size. Vomerine teeth absent. Chin with well-developed, often small, barbel. Branchiostegal rays seven. Gill rakers of outer branchial arch short or of moderate length. Otolith with ostium approximately equal to the cauda (1:1 to 1:1.4), the crista superior as long as or longer than the crista inferior; otolith thickness 20–22% of its length (Paulin, 1983). Scales small, covering body and head; extending onto loose membranes enveloping the bases of dorsal and anal fins; lateral line pores at ends of short tubes from naked strip not associated with individual scales. Two dorsal fins and one anal fin, first dorsal slightly taller than, immediately adjacent to and joined to second by low membrane, with 8–14 rays, first ray not prolonged; second dorsal and anal fins with elongate bases, of nearly uniform height; caudal fin separate, rounded or truncate. Ventral fins composed of five or six rays, the two outermost longest and projecting beyond fin membrane but not greatly prolonged.

Etymology. The feminine name Pseudophycis is an amalgamation of the Greek words pseudos, meaning “lie” or “false”, and phykis, “a fish living among seaweeds” (Brown, 1954) and the source word of the scientific name for the North Atlantic gadid genus Phycis Walbaum, 1792, in reference to the overall resemblance of species of the two genera to one another.

Distribution. Species of the genus are endemic to coastal waters of temperate Australia and New Zealand.

Remarks. Species referable to the genus Pseudophycis were described or treated as members of seven morid genera based on the superficial resemblances of species in the genera to one another. These include: Gadus Linnaeus, 1758, type species Gadus morhua Linnaeus, 1758, by subsequent designation of Jordan and Gilbert (1883: 802); Enchelyopus Bloch and Schneider, 1801, type species Gadus cimbricus Bloch and Schneider, 1801, by subsequent designation of Jordan and Evermann (1898: 2560); Lota Oken, 1817, type species Gadus lota Linnaeus, 1758, by subsequent tautonomy (Fricke et al., 2019); Lotella Kaup, 1858, type species Lota phycis Temminck and Schlegel, 1846, by monotypy and Physiculus Kaup, 1858, type species Physiculus dalwigki Kaup, 1858, by monotypy (see species treatments for details). Austrophycis Ogilby, 1897, caused particular confusion until Sazanov (2001: 343) identified the type specimen of A. megalops as P. breviuscula (Richardson, 1846). The genus Pseudophycis comprises four species.

Genetic analysis. Concerted efforts to document genetic sequences for the CO1 gene across Australasian fish species as part of the Fish Barcode of Life project provided an additional means of testing suspect species concepts. A preliminary comparison of sequences of New Zealand and Australian specimens identified as P. bachus and P. barbata in BOLD had already revealed potentially cryptic sister species on either side of the Tasman Sea. Sequences for specimens identified as P. bachus had low divergence among specimens within Australia (0.002) and within New Zealand (0.000) but high sequence divergence in the pooled data (0.086) typical of species pairs (Smith et al., 2008: 8, fig. 5).

A comparison of a larger set of sequences for Australian and New Zealand specimens identified as species of Pseudophycis, plus sequences of specimens of Auchenoceros punctatus as an outgroup, generated a tree with five inferred species branches, four having a common basal node for vouchers identifiable as P. barbata, P. breviuscula, P. bachus and P. palmata (Ward pers. comm.; fig. 1). Importantly, the branches of P. bachus and P. palmata, previously thought to be conspecific, are of about the same lengths as those of P. barbata and P. breviuscula, despite the morphological differences distinguishing the latter two (Table 1).

1. Caudal margin truncate with angular corners in specimens larger than about 150 mm SL, central caudal fin rays distinctly shorter than those extending to the corners; basal portion of pectoral fin with distinct dark blotch or spot 2

– Caudal margin rounded with rounded corners, central caudal fin rays equal in length or longer than those extending to the corners; no distinct dark blotch or spot basally on pectoral fin 3

2. Dark blotch or spot basally on pectoral fin extending dorsally onto body; second dorsal fin with 40–45 rays; anal fin with 42–48 rays; total vertebrae 44–46 Pseudophycis bachus

– Dark blotch or spot basally on pectoral fin not extending dorsally onto body; second dorsal fin with 47–56 rays; anal fin with 50–57 rays; total vertebrae 47–50 Pseudophycis palmata

3. Scales above lateral line 16–22; second dorsal fin with 54–59 rays; anal fin with 54–63 rays; pyloric caeca 14–20; total vertebrae 48–51 Pseudophycis barbata

– Scales above lateral line 7–9; second dorsal fin with 44–52 rays; anal fin with 49–56 rays; pyloric caeca 6–9; total vertebrae 42–45 Pseudophycis breviuscula