Nesting sites of the naked dragonfish Gymnodraco acuticeps have been identified in 15–35 m water under fast ice adjacent to McMurdo Station, making it possible to examine embryonic development and early larval growth. Egg-laying (predominantly in October) is preceded by a distinctive whirling behavioural pattern driven by the male prodding the side of the female's abdomen. The eggs (3.42 ± 0.19 mm in diameter) are laid on rocks as a single adherent layer (c. 2500 per patch). Development is unusually protracted, the first cleavage occurring after about 24 hr at about −1.9°C. Hatching occurs about 10 months post-fertilization, beginning soon after the sun rises above the horizon. During this period one of the parents may act as a guard in an attempt to keep predators at bay. Upon hatching, the larvae (12.09 ± 0.36 mm long) swim towards the surface ice where they presumably seek refuge. Yolk absorption is complete in about 15 days. Larvae (grown in aquaria at a density of 0.7 larvae l−1) display an average daily growth rate of 0.42% over nine weeks. Hatching in aquaria can occur up to 100 days in advance of that seen in the field, suggesting that under natural conditions hatching may be delayed until an appropriate stimulus (such as the return of the sun) is received.

The demersal fish fauna of the southern and eastern Weddell Sea is described. The following species were recorded for the first time in this area: Aethotaxis mitopteryx, Bathyraja eatoni, B. Maccaini, B. sp2 (FAO-list), Bathydraco marri, Dissostichus mawsoni, Macrourus holotrachys, Muraenolepis sp., Notothenia coriiceps, Notothenia kempi, Psilodraco spec. and Trematomus nicolai. In terms of biomass the dominant species on the very narrow eastern continental shelf were Chionodraco myersi (49%), Trematomus eulepidotus (11%), C. hamatus (7%), T. lepidorhinus (6%), Pagetopsis maculatus (5%) and T. scotti, Cryodraco antarcticus, Cygnodraco mawsoni and Pleuragramma antarcticum (4% each). The highest density of individuals and greatest biomass was found between 400 and 650 m water depth. Here, C. myersi, T. eulepidotus and T. lepidorhinus dominated the catches. The shallow shelf area was inhabited by smaller species such as T. scotti, T. centronotus, P. maculatus, Artedidraco skottsbergii, A. shackletoni, and Prionodraco evansii. In the southern Weddell Sea Akarotaxis nudiceps, Dolloidraco longedorsalis, Gerlachea australis, Pleuragramma antarcticum, and Trematomus loennbergi were dominant. Members of the Channichthyidae occurred only occasionally, most of these are Dacodraco hunteri. The biomass of the demersal fish fauna was estimated to be 0.3 to 1.6 t km−2 on the Vestkapp shelf and 0.1 to 0.4 t km−2 for Gould Bay. Biomass values greater than 1.0 t km−2 were found at the shelf edge.

The diet of Cygnodraco mawsoni Waite 1916 and Gymnodraco acuticeps Boulenger 1902 (Pisces: Bathydraconidae) was studied in the Cooperation and Cosmonaut seas in the depth range 200–400 m during the summer 1988. Stomach content analysis showed that both species are piscivorous predators but with different feeding habits. Cygnodraco mawsoni fed mostly on young notothenioid fish, regularly complementing these with pelagic, Euphausia superba, and benthic crustaceans, such as amphipod gammarids and mysids. In contrast, G. acuticeps relied mostly on mesopelagic fish of the family Myctophidae. Although C. mawsoni and G. acuticeps occupy similar depths in the Cosmonaut Sea, different feeding habits appear to limit the probability of interspecific competition for food.