Threatened Species Nomination 2020 Details of the nominated species or subspecies NAME OF SPECIES (OR SUBSPECIES) Scientific name: Brachaelurus colcloughi (Australian Synonym: Heteroscyllium colcloughi) Common name(s): Colclough's Shark, Bluegray carpetshark, Bluegrey catshark , Bluegrey shark, Southern blind shark, Colclough’s Blind Shark TAXONOMY Provide any relevant detail on the species' taxonomy (e.g. authors of taxon or naming authority, year and reference; synonyms; Family and Order). Brachaelurus colcloughi (Ogilvy 1908). Kingdom: Animalia Phylum: Chordata Class: Chondrichthyans Subclass: Elasmobranchii Order: Orectolobiformes Family: Brachaeluridae Genus: Brachaelurus Species: Colcloughi Brachaelurus colcloughi was first described in 1908 (Ogilvy 1908). It is one of only two extant species within the carpet shark (Orectolobiformes) family Brachaeluridae (blind sharks), the other being the partially sympatric blind shark (B. waddi; Compagno 2001). There was some uncertainty about the taxonomy until the Queensland Museum analysed two further samples and confirmed the genus (Compagno 2002). It was sometimes classified in the genus Heteroscyllium (e.g. Compagno 2001; Last and Stevens, 2009), however more recently molecular analysis confirmed that the genus Heteroscyllium is synonymous with Brachaelurus (Naylor et al. 2012). The importance of addressing the conservation status of B. colcloughi is heightened by the species belonging to a highly evolutionarily distinct lineage (Stein et al. 2018). There is no evidence to suggest that this species hybridises with others. CONVENTIONALLY ACCEPTED Is the species’ taxonomy conventionally accepted? Yes. No If the species is not conventionally accepted please provide the following information required by the EPBC Regulations 2000: • a taxonomic description of the species in a form suitable for publication in conventional scientific literature; OR • evidence that a scientific institution has a specimen of the species, and a written statement signed by a person who is a taxonomist and has relevant expertise (has worked with, or is a published author on, the class of species nominated), that the species is considered to be a new species. n/a Page 2 of 17 DESCRIPTION Provide a description of the species including where relevant, distinguishing features, size and social structure How distinct is this species in its appearance from other species? How likely is it to be misidentified? Brachaelurus colcloughi (Fig. 1 & 2) is a relatively small shark, with a maximum recorded size of 88 cm total length (TL; Rigby et al. 2016). It has a stout body, and a wide, slightly flattened and narrowly arched head (around 22% of TL). It has a moderately long and blunt snout (prenarial and preoral snout around 2.5% and 6% of TL respectively). A pair of long barbels preceeding the nostrils are distinctive, with enlarged posterior flaps midway along each barbel. It has a small, transverse and subterminal mouth ahead of the large, elongated-fusiform eyes, which are placed high dorsally and are not elevated. When removed from the water, the bluegrey carpetshark will close its eyes like the closely related Blind shark (Brachaelurus waddi). It has large, rounded spiracles positioned just behind the eyes, and five short pairs of gill slits, with the fourth and fifth pair relatively more closely spaced (Compagno 2002). Brachaelurus colcloughi has large, rounded pectoral and pelvic fins. It has two spineless dorsal fins placed far back anterially, both free with angular rear tips. The anterior dorsal fin is clearly smaller (less than 0.9 times the height and base length). The spineless anal fin, also with a free rear tip, is positioned far from the base of the caudal fin and is less than half the size of the first dorsal fin (Compagno 2002). The caudal fin is long (around one quarter of total length) and it has a short precaudal tail. Adult colouring ranges from grey to golden brown dorsally and laterally and are white ventrally, with white patches on the anterior webs of dorsal fins. Young sharks have conspicuous black and white saddle-shaped markings along their backs, dorsal fins and caudal fin, which fade with growth. It has small, smooth and non-overlapping dermal denticles (Compagno 2002). As with many cryptic sharks, it is unknown whether it is social. Another species of Orectolobiformes shows social grouping behaviour (Armansin et al. 2016) but this needs further investigation for B. colcloughi. Although B. colcloughi have some morphological similarities with the closely related B. waddi, it is distinguishable by colour, morphology of the nasal barbels, location of the anal fin, and the size variation of the dorsal fins (Last and Stevens, 2009). Although it may have been mistaken for B. waddi in fisheries records in past decades, a greater understanding of its anatomy now means these species are unlikely to be confused. It is also very unlikely to be confused with other sympatric Orectolobiformes due to substantial morphological differences. DISTRIBUTION Provide a succinct overview of the species’ known or estimated current and past distribution, including international/national distribution. Provide a map if available. Is the species protected within the reserve system (e.g. national parks, Indigenous Protected Areas, or other conservation estates, private land covenants, etc.)? If so, which populations? Which reserves are actively managed for this species? Give details. Brachaelurus colcloughi is endemic to shelf waters off central and southern Queensland and northern New South Wales. Its recorded distribution is limited, ranging from the Hardline Reefs off central Queensland to Julian Rocks, off Byron Bay, NSW ) (Fig 3; Kyne et al. 2011). Occurrence reports from northern QLD are unsupported (Kyne et al. 2011). Its extent of occurrence is an area covering approximately 8° of latitude, however its core range is considered to be much narrower (<2°; Kyne et al. 2015). Prior to 2016, its core range was thought to be within Moreton Bay (56% of known records gathered from museums, bycatch landings and literature records; Kyne et al. 2011). Despite rigourous surveying of suitable habitat in southerneastern Queensland from 2008-2011, there were very few observations outside of Moreton Bay. In 2016, a confirmed sighting of 27 individuals by Rigby in the Swain Reef areas indicates a significant extension of its limited distribution and indentifies a second area of Page 3 of 17 critical habitat (Rigby et al. 2015). The restricted distribution of B. colcloughi makes it inherently vulnerable to disturbances and population decline (Compagno 2001). B. colcloughi is known to refuge in caves during the day, and forage at night, making it susceptible to night trawling activities (Kyne et al. 2011). Its home range and seasonal movements is not known. There are no captive breeding populations or proposed re-introduction plans. The distribution of B. colcloughi is partially covered by marine parks, some of which is designated as sanctuary zones in which no extractive activities are permitted (Kyne et al. 2015), for e.g. 15% of Moreton Bay Marine Park is fully protected, with trawling also restricted in some other areas . It is also partially protected in the Great Barrier Reef Marine Park, however trawling is permitted in Swain Reef National Park, in which 27 of the known records were gathered. In NSW, it is found in Julian Rocks Aquatic Reserve (Byron Bay; Kyne et al. 2011) and the Cape Byron Marine Park (Kyne et al. 2015) which offers some protection. These reserves are not actively managed for B. colcloughi, and no systematic monitoring is in place to assess the efficacy of zoning for this species. B. colcloughi are known to forage in seagrass areas , and these habitat areas are protected under the Queensland Fisheries Act 1994 but not nationally. BIOLOGY/ECOLOGY Provide a summary of biological and ecological information. Include information required by the EPBC Regulations 2000 on: • life cycle including age at sexual maturity, life expectancy, natural mortality rates • specific biological characteristics • habitat requirements for the species • for fauna: feeding behaviour and food preference and daily seasonal movement patterns • for flora: pollination and seed dispersal patterns Females are classified as mature at 54.5 cm and males at 61 cm TL (Kyne et al. 2011). Such sexual dimorphism difference is atypical in viviparous elasmobranchs (Last and Stevens 2009). Age at maturity, growth rate and longevity are not known, however in the closely related B. waddi, males reach maturity at 7.3 years (females unknown) and have been known to live for 19 years (Norén 2013). From this, generation length is estimated to be 15.5 years. Little is known about the breeding system, and breeding success. It demonstrates aplacental yolksac viviparity, in which embryonic nutrition is provided by the yolk of a single ovum and have one of the lowest litter sizes of viviparous species in this order, with 6-7 pups born at 17 – 19cm TL (Kyne et al. 2011). The duration of the breeding season and the conditions needed for breeding are not known, although gravid females and fertile males have been observed in austral winter months and winter parturition is expected (Kyne et al. 2011). The frequeny of breeding is also unknown, however B. waddi and other Orectolobiformes are known to have biennial and triennial cycles (Norén 2013, Huveneers et al. 2007). This may be a reasonable expectation with B. colcloughi which have a lengthy ovarian cycle (Kyne et al. 2011). Given its late maturity, relatively long life expectancy, potentially non-annual breeding periodicity and low litter sizes, B. colcloughi populations are likely to be sensitive to disturbances, and a greater understanding of its reproductive capacity is essential for assessing the viability of its populations. B. colcloughi is a benthic species. It is restricted to shelf waters, and are generally found at around 100m depths (range: <4m – 217m; Kyne et al. 2011, Weigmann 2016). It is a nocturnal species which refuges in topologically complex habitat such as drop-offs, ledges, ship wrecks and reef-associated habitat during the day (Ceccarelli et al.