Observations on the Reproductive Biology of Three Catsharks
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Journal of the Marine Biological Association of the United Kingdom, 2011, 91(6), 1157–1164. # Marine Biological Association of the United Kingdom, 2010 doi:10.1017/S0025315410001670 Observations on the reproductive biology of three catsharks (Carcharhiniformes: Scyliorhinidae: Asymbolus and Figaro) from the continental shelf of southern Queensland, Australia peter m. kyne1,2, anthony j. courtney3 and michael b. bennett4 1School of Biomedical Sciences, University of Queensland, St Lucia, Queensland, 4072, Australia, 2Present address: Tropical Rivers and Coastal Knowledge, Charles Darwin University, Darwin, Northern Territory, 0909, Australia, 3Southern Fisheries Centre, Department of Employment, Economic Development and Innovation, Deception Bay, Queensland, 4508, Australia, 4School of Biomedical Sciences, University of Queensland, St Lucia, Queensland, 4072, Australia Three species of Australian endemic catsharks (grey spotted catshark Asymbolus analis, orange spotted catshark A. rubigi- nosus and Australian sawtail shark Figaro boardmani) were collected from the trawl grounds of a highly seasonal commercial fishery off southern Queensland, Australia. Specimens were collected on the mid to outer continental shelf at depths between 78 and 168 m. This study provides the first information on the reproductive biology of these three poorly-known species. Mature female and male A. analis were observed from 455 mm total length (TL), mature female A. rubiginosus from 410 mm TL, mature male A. rubiginosus from 405 mm TL, mature female F. boardmani from 402 mm TL and mature male F. boardmani from 398 mm TL (although a lack of immature specimens precluded more accurate assessments of size at maturity). The reproductive mode of all species was confirmed as single oviparous (carrying only one egg case in each uterus at a time). Ovarian fecundity (the number of vitellogenic follicles) ranged from 7–20 in A. analis,5–23inA. rubiginosus and 9–13 in F. boardmani. Several indicators suggest that Asymbolus catsharks off southern Queensland are reproductively active year-round. The proportion of female A. rubiginosus carrying egg cases was highest in spring (60%), intermediate in autumn (50%) and lowest in winter (44%). Keywords: Scyliorhinidae, Asymbolus analis, Asymbolus rubiginosus, Figaro boardmani, Queensland, East Coast Trawl Fishery, size at maturity, reproductive seasonality Submitted 13 April 2010; accepted 20 August 2010; first published online 18 October 2010 INTRODUCTION The demersal elasmobranch fauna of the outer continental shelf and upper slope off southern Queensland (eastern The catsharks (Elasmobranchii: Carcharhiniformes: Australia) includes three poorly-known Australian endemic cat- Scyliorhinidae) represent the most speciose shark family sharks: grey spotted catshark Asymbolus analis (Ogilby, 1885) with 120+ valid species recognized globally (updated from (eastern Australia from southern Queensland to Victoria; 25– Compagno, 2005). While the family is global in occurrence, 200 m depth); orange spotted catshark Asymbolus rubiginosus many species have limited distributions. The Australasian Last, Gomon & Gledhill, in Last, 1999 (eastern Australia from region has a high degree of endemism, with 34 scyliorhinid southern Queensland to Tasmania; 25–540 m depth); and species recorded from Australian waters (Compagno et al., Australian sawtail shark Figaro boardmani (Whitley, 1928) 2005; Last & Stevens, 2009). Despite their diversity, the (eastern, southern and western Australia from southern family remains poorly-known, with limited to no biological Queensland to Western Australia including Tasmania; 130– or ecological information available for the vast majority of 640 m depth) (Last et al., 1999; Kyne et al.,2005;Last& species. Apart from published studies on the common Stevens, 2009; present study). Kyne et al. (2005) provided inshore draughtboard shark Cephaloscyllium laticeps some basic information on reproduction in A. analis, but this (Dume´ril, 1853) of southern Australia (Awruch et al., 2008, was based on only five dissected mature females. 2009), and some limited reports on sizes at sexual maturity These three catshark species are discarded bycatch of the (Last & Stevens, 2009), information on the reproductive Queensland East Coast Trawl Fishery (QECTF), a multi-species biology of Australian scyliorhinid sharks is lacking. benthic commercial fishery targeting prawns (Penaeidae) and scallops (Pectinidae). Off southern Queensland, the large eastern king prawn Penaeus plebejus is fished on the outer con- Corresponding author: P.M. Kyne tinental shelf in a seasonal (generally between May and August) Email: [email protected] ‘deepwater’ fishery in depths of 90–300 m. Catshark specimens 1157 Downloaded from http:/www.cambridge.org/core. Department of Agriculture & Fisheries, on 05 Sep 2016 at 03:58:20, subject to the Cambridge Core terms of use, available at http:/www.cambridge.org/core/terms. http://dx.doi.org/10.1017/S0025315410001670 http:/www.cambridge.org/core/terms Downloaded from 1158 peter m. kyne 168 m) off southern2004 Queensland, from the Australia mid (26 Specimens to were outer collected continental between shelf March (depths 2001 of and 78– February MATERIALS AND METHODS F. boardmani and ovarianmaturity, fecundity) of reproductiveinformation on the mode,gaps reproductive in biology reproductive their (sex-ratios,catshark basic size bycatch biology. at seasonality is This irregular)lected paper in from presents order preliminary a towater shallower address sector of water knowledge the sector QECTFwere (though of primarily some collected specimens the were from col- QECTF, the trawl where grounds of this deep- was calculated asmass (gonad (OM) mass/body and mass) TLCL for females. and Gonadosomatic TL indexrelationships were (GSI) between testes examined massexamine (TM) for the and onset males, TL of maturity and andof (possible between the only between pelvic in fin ovary in to males the to posterior the tip nearestnearest of millimetre, the from decigram. longest the clasper. Inner point(both To of clasper insertion with length attached (CL) epigonal was tissues) measured present). were weighed tofully the developed oviducal glands,ovaries uteri with and yellow eggoviducal glands, cases vitellogenic slightly expanded may uteri) follicles be orsmall mature white (developed follicles uteri), adolescent (incompletely developed(undeveloped ovaries ovaries, with undifferentiated only didymides oviducal highly glands, coiled). thin Femalesfied and were elongated classed claspers, as testesextended immature developed but and uncalcified, lobular, developing epi- uncalcified testes) claspers, or undeveloped mature testes), (calci- Males adolescent (claspers were classedand as females immature (Ellisto (if the & nearest they gram. Shackley,ventral Maturity possessed surface stages 1997; to short, were the Ebert the assessed nearest millimetre. for distant Mass males margin was measured of the caudallengths of fin 12.8 was or50.8 22.0 measured mm, m. on codend Catsharks mesh were the with size snap-frozen 44.5 at three or sea. 2-seam 47.6Collection mm) Florida with was headrope Flyerporated by nets into (net commercial the body full(N otter-board dataset mesh for trawlers size thatof fitted species the presented fishery) here. specimen (Table collected 1). in Data summeralmost from from the specimens no shallow of sampling watercollected sector conducted from in onlylected. summer a (with Therefore, few onlyation months, one the and mostly the vast in months/seasonslimited in winter, both majority which the with specimens numberthan of were of about col- 90 specimens m specimens available depthAugust. and for Outside catshark were examin- of by these catch months, istrawl vessels minimal. This fish fishery; waters the shallower fisherywere generally collected operates from between a highly May seasonal and sector of the Queensland width (OGW) was calculatedpossible, compared in between mature seasons. females, Average and oviducal where gland 153 Reproductive systems were removed and testes and ovaries Total length (TL), the distance from the tip of the snout to ¼ http:/www.cambridge.org/core 8 31 5 females) examined by Kyne ′ –153 8 50 from southern Queensland. ′ E) (Table 1). The vast majority of specimens . http://dx.doi.org/10.1017/S0025315410001670 et al. ≤ 4 mm diameter, incompletely developed . Department ofAgriculture&Fisheries A. analis et al. , A. rubiginosus (2005) were incor- ≥ ∗ 5 mm diameter, 100, and where A. analis et al. 8 31 ′ A. analis –27 , 2006). , on ), the 8 49 and 05 Sep2016 at03:58:20 ′ S , subjectto theCambridgeCore termsofuse,available at Table 1. Summary of months of collection, location, depth, sample size, size-range and mass-range for scyliorhinid sharks captured off southern Queensland from the trawl grounds of the Queensland East Coast Trawl Fishery. Species Months of collection Latitudes Longitudes Depth-range Total CFSize-range (mean + SD) Mass-range (mean + SD) (2001–2004) N (mm total length) (g) Asymbolus analis March 2001, September 2001, October 26837′ –27849′S 153831′ –153849′E 81–165 m 29 15 14 C: 278–495 (404.3 + 88.5) C: 57–631 (279.3 + 180.3) 2001, July 2002, May 2003, July 2003, F: 285–515 (430.0 + 86.9) F: 75–423 (269.5 + 127.0) September 2003, February 2004 Asymbolus August 2001, October 2001, July 2002, 26850′ –27849′S 153834′ –153850′E 78–168 m 122 66 56 C: 410–520 (446.5 + 23.4) C: 178–375 (261.9 + 44.8) rubiginosus May 2003, July 2003, September 2003 F: 380–495 (439.7 + 19.0)