First observation of a skate egg case nursery in the Ross Sea.

Areas of importance to Southern Ocean skates are poorly defined. Here, we identify a deepwater skate egg case nursery in a discrete location at ~460 m depth off Cape Adare in the Southern Ocean. This is the first confirmed observation of a skate nursery area in the Ross Sea and only the second observation for the Southern Ocean. The morphology and size of the egg cases were consistent with the genus Bathyraja and most likely belong to the Bathyraja sp. (cf. eatonii). The nursery occurs within the "no take" General Protection Zone of the Ross Sea region marine protected area, where commercial fishing is prohibited.

Sharks checking in to the sponge hotel: First internal use of sponges of the genus Agelas and family Irciniidae by banded sand catsharks Atelomycterus fasciatus.

Trawl surveys within and surrounding two northwestern Australian marine parks revealed banded sand catsharks Atelomycterus fasciatus (family Atelomycteridae) taking refuge within large sponges of the family Irciniidae (Demospongiae: Dictyoceratida) and the genus Agelas (Demospongiae: Agelasida: Agelasidae). Five sponges contained a total of 57 A. fasciatus, comprising both sexes and both immature and mature individuals ranging from 102 to 390 mm total length (TL). In the same surveys, only five A. fasciatus were captured unassociated with sponges, suggesting that sponges are an important microhabitat for A. fasciatus and may provide a daytime refuge from predators. A southerly range extension is also reported for this species.

What came first, the shark or the egg? Discovery of a new species of deepwater shark by investigation of egg case morphology.

Apristurus ovicorrugatus, a new species of deepwater catshark, is described from northwestern Australia. Unique egg cases belonging to an unknown species of Apristurus prompted a more detailed investigation of Apristurus specimens off northwestern Australia. One specimen previously identified as A. sinensis collected off Dampier Archipelago was found gravid with a single egg case. Removal of this egg case confirmed that this species was responsible for producing the unique egg cases previously recorded. The egg cases of this species have strong T-shaped longitudinal ridges on the dorsal and ventral surfaces which are unique in the genus Apristurus. The ridges most closely resemble those present in Bythaelurus canescens from South America, but are larger and always T-shaped. The holotype is closest morphologically to A. sinensis but differs in having a medium brown buccal cavity (vs. jet black), ridged egg cases (vs. smooth egg cases), fewer intestinal spiral valve turns and larger pectoral fins. The holotype is also similar, and closest on a molecular level, to A. nakayai with which it shares a unique synapomorphic character, the white shiny iris (apomorphic within the genus). A late-term embryo removed from an egg case superficially resembled the holotype except in having two parallel rows of enlarged dermal denticles on the dorsolateral predorsal surface. Recent nomenclatural changes to the genera Apristurus and Pentanchus are discussed and challenged. This study highlights the important contribution that egg case morphology has on oviparous elasmobranch taxonomy.

Further description of the Kerguelen sandpaper skate Bathyraja irrasa (Rajiformes: Arhynchobatidae) based on additional specimens, including egg cases and embryos.

Adult specimens, additional juvenile specimens, egg cases and embryos were used to provide a more detailed anatomical description of the Kerguelen sandpaper skate Bathyraja irrasa, a species of skate endemic to the Kerguelen Plateau and listed as Vulnerable by the IUCN Red List of Threatened Species. The morphological and meristic data reveal a relatively high level of intraspecific variation, mostly related to size. Egg cases are described for the first time and were shown to vary in colour and fouling depending on the length of time spent in the marine environment. Embryos removed from egg cases represent all stages of embryonic development in this species and include the largest embryo recorded for this species, i.e., 230 mm total length (LT ), which increases the range of size at hatching of B. irrasa to 178-230 mm LT . A number of morphometric and meristic characters varied ontogenetically in B. irrasa, in particular relative tail length, number of tail thorns in the median row and the size of orbits. This study highlights the importance of describing intraspecific variation in species and the importance of egg cases to taxonomic and biological research on oviparous species.

Description of the egg cases and juvenile colouration in two catsharks of the genus Atelomycterus (Carcharhiniformes: Scyliorhinidae).

Descriptions of egg cases and hatchlings of the Bali catshark Atelomycterus baliensis and the Australian marbled catshark Atelomycterus macleayi are provided. Comparisons are made with two of their congeners, banded sand catshark Atelomycterus fasciatus and coral catshark Atelomycterus marmoratus. The Atelomycterus egg cases have the same general morphology, i.e., elongate with anterior and posterior waists, a depressed and truncate anterior end sometimes with attachment fibres, a medially tapered posterior end with two horns sometimes terminating in short, tightly curled tendrils and four respiratory fissures (one at each left corner on opposing sides). Morphometric measurements taken of the egg cases of the four species differed significantly when subjected to multivariate analysis, with unique characters enabling distinction between them. The morphological characters that best distinguished the Atelomycterus species from each other were anterior border width, posterior waist width and posterior case width. Thus, egg case morphology could be used to distinguish the egg cases of the four Atelomycterus species examined, consistent with other studies on scyliorhinid and pentanchid egg cases. Colouration of A. baliensis and A. macleayi juveniles was similar to that of other Atelomycterus juveniles in being pale with a series of dark-brown distinct dorsal saddles along the body, blotches and sometimes with a low number of small dark spots.