Andrew L. Stewart

Lampanyctus mendeleevi sp. nov. is described from the New Zealand-east Australian region of the western South Pacific Ocean. It has relatively long pectoral fins, no cheek photophores, no luminous tissue at the base of the adipose fin, and an infracaudal gland extending the entire length of the caudal peduncle expanded to touch or nearly touch the AOp series.

The Channichthyidae, a monophyletic fish group belonging to the suborder Notothenioidei, are uniquely adapted to the polar environment. However, while their physiology has been extensively studied, studies on their ecology are relatively rare. Here, we investigated the trophic ecology of seven icefish species (Chaenodraco wilsoni, Chionobathyscus dewitti, Chionodraco hamatus, Dacodraco hunteri, Neopagetopis ionah, Pagetodes antarcticus and Pagetopsis macropterus) by using the traditional morphometric approach to assess the relationship between form and feeding function. The suction index (SI), the mechanical advantage in jaw closing (MA) and nine morphological traits related to feeding structures have been analysed. Icefish species are characterised by non-protractible, elongate jaws and a wide gape; such morphological features influence the low values of both MA and SI, supporting their ram-feeding habit. The ecomorphological differences among species resulted mainly determined by the anatomical structures related to SI. Such differences do not seem to be determined primarily by the type of prey, as is the case in other taxonomic groups of Notothenioidei, but rather by phylogenetic proximity. A 3D animation was developed to visualise the different feeding modes of two icefish species (C. hamatus and P. macropterus) which are characterised by different approaches to prey.

A new species of dragonfish Eustomias (Nominostomias) robertsi is described from the western South Pacific Ocean. The new species, the first record of a member of Eustomias (Nominostomias) Group III (sensu Gibbs et al. 1983) from the region, it is most similar to Eustomias suluensis in barbel morphology. However, it has a smaller proximal and distal bulb distance, the smallest distal inter–bulb value in the group, and much longer terminal filaments. Comments are also provided on the morphology of the diagnostic features on the barbel of Eustomias trewavasae, including an important character overlooked in the original description of the species. The barbel morphology is redescribed taking this into account. A brief observation is made recording the first record of the subgenus Triclonostomias from the western South Pacific Ocean.

The genus Dichichthys was resurrected for five species previously allocated to the genus Parmaturus in the family Pentanchidae. Supraorbital crests on the chondrocranium distinguish Dichichthys from Parmaturus and other members of the family Pentanchidae. A new family, Dichichthyidae, has been proposed to contain Dichichthys. The sequence of the NADH2 mitochondrial gene confirms the placement of Dichichthys outside of the Pentanchidae family, as well as separate from the Atelomycteridae and Scyliorhinidae families. Dichichthys albimarginatus was described using a holotype collected off the coast of New Caledonia. A second juvenile specimen collected off the coast of Papua New Guinea was tentatively assigned as D. cf. albimarginatus. Dichichthys bigus is known from the holotype collected in the Coral Sea off the coast of Queensland, Australia. A new, parasite-afflicted underwater observation was reported further north of Queensland. The type species Dichichthys melanobranchus, previously only known from juvenile specimens, was redescribed based on adult specimens. Dichichthys nigripalatum is known from the holotype collected off Sumbawa, Indonesia, and a tentatively identified photo record from West Java. Dichichthys satoi n. sp. is described from the West Norfolk Ridge and off the North Island of New Zealand. Members of the genus Dichichthys have unique curved egg cases which have pliable ridges made up of numerous fibres and long coiled tendrils on the posterior end.

This note reports on eight observations of inverted swimming behavior by species of ceratioid whipnose anglerfishes in the genus Gigantactis, from the Caribbean, tropical east Atlantic, tropical western Indian Ocean, the north‐east and north‐west Pacific and south‐west Pacific. It covers four putative species and strongly suggests that this is the normal behavior for the genus. A possible reason is briefly discussed. In addition, a new depth record of 5866 m for the ceratioid anglerfish is recorded.

The eastern Australian flatback mangrove goby Mugilogobius platynotus (Günther 1861) is recorded for the first time from Aotearoa, New Zealand. Three voucher specimens (two males and one female) were collected using fish traps submerged in tidal drains of a saltmarsh wetland edged by mangroves adjacent to Ngunguru River, Northland. Key characters for identification: the colour of freshly thawed specimens, meristic counts, and morphometric measurements are presented and compared with the same characters described by Larson (2001) for all Mugilogobius . We discuss this major range extension from its natural Australian distribution, concluding it is an adventive species, probably carried across the Tasman Sea into New Zealand waters by shipping, not ocean currents. Our analysis of goby species recorded from northern New Zealand mainland waters concludes seven (86%) are probably adventive and introduced from Australia. We recommend a further survey of mangrove and saltmarsh estuary habitats to discover if this new goby has established a breeding population and is expanding its current limited distribution within northern New Zealand.

A single specimen of a new Bathyraja skate was collected by the authors in 2003 during a survey of the deepwater biota of the northern Tasman Sea by the New Zealand FRV Tangaroa. This skate, labelled the ‘blonde skate’ by voyage participants, is uniformly white on all surfaces of the body and the skin is partly translucent. It belongs to a subgroup of Bathyraja with a large, almost smooth, quadrangular disc and well-developed and equally spaced median tail thorns. Other similar and probably closely related Bathyraja specimens have been caught in seas to the south of New Zealand since the discovery of this species, but their identity is yet to be confirmed.

The high intraspecific variation among and the conservative external morphology of Merluccius spp. have resulted in serious identification difficulties. Four hundred and twenty fresh and preserved specimens of Merluccius were analyzed, including the type series of Merluccius australis, M. tasmanicus and M. hubbsi; specimens of M. hubbsi from Argentina, Brazil and Uruguay, and individuals of M. australis from Argentina and New Zealand were examined. The nomenclatural status of the type specimens of M. australis is discussed and the designation of a lectotype and a paralectotype is proposed. The comparative study of morphology, meristic, traditional and landmark-based morphometry, both external and internal, and through DNA-based Barcoding molecular tools demonstrates that Merluccius tasmanicus is a junior synonym of Merluccius australis. Meristic and morphometric characters of types of M. tasmanicus completely overlap those of M. australis, whereas M. hubbsi show fewer scales along the lateral line, total vertebrae, second dorsal and anal-fin rays. A trend of a longer snout and wider head in M. australis and M. tasmanicus, and larger eyes and longer pelvic fins, in M. hubbsi was observed. While discriminant characters were found in the internal elements (hyomandibula, urohyal and sagitta otolith) between M. hubbsi and M. australis, none were observed between M. australis and those reported for M. tasmanicus. DNA barcoding analyses found no evidence of the existence of other species of Merluccius besides M. hubbsi and M. australis.

Bathylagichthys kobylianskyi n. sp. is described from specimens collected during fisheries surveys of the Exclusive Economic Zone of New Zealand. It was previously misidentified as B. problematicus, from which it differs in having fewer vertebrae (43–45 versus 49–51) and more gill rakers (usually 27–31 versus 25–28). Bathylagichthys kobylianskyi n. sp. is closely related to B. greyae of the Atlantic Ocean as both have two branchiostegal rays and a short supraorbital. The latter species differs from B. kobylianskyi n. sp. in having a more slender body, fewer gill rakers and modally higher number of vertebrae and anal-fin rays.