Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences
Shopping Cart: ( empty )
You are here: Home > Journals > MF > MF05076
RESEARCH ARTICLE
Contents Vol 57(1)

Determining reproductive parameters for population assessments of chondrichthyan species with asynchronous ovulation and parturition: piked spurdog (Squalus megalops) as a case study

J. Matías Braccini A B C , Bronwyn M. Gillanders A and Terence I. Walker B
+ Author Affiliations
- Author Affiliations

A Southern Seas Ecology Laboratories, Darling Building DP 418, School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia.

B Primary Industries Research Victoria, PO Box 114, Queenscliff, Vic. 3225, Australia.

C Corresponding author. Email: matias.braccini@adelaide.edu.au

Marine and Freshwater Research 57(1) 105-119 https://doi.org/10.1071/MF05076
Submitted: 26 April 2005  Accepted: 10 October 2005   Published: 17 January 2006

Abstract

Population assessments of chondrichthyan species require several key parameters of their reproductive biology, which were estimated for Squalus megalops (Macleay, 1881). Length-at-maturity differed depending on the criterion adopted for defining maturity. In the case of males, length-at-maturity was smallest when condition of seminal vesicles was adopted as a maturity criterion. For females, length-at-maturity was smallest when the largest follicle diameter >3 mm was adopted as the criterion for maturity; this was appropriate only as an indicator of the onset of maturity. Mature males are capable of mating throughout the year. Females have a continuous asynchronous reproductive cycle. The sex ratio of embryos is 1 : 1 and litter size and near-term embryo length increase with maternal length. Females have an ovarian cycle and gestation period of two years. This was reflected in the differences found between the maturity and maternity ogives. Although all females are mature at 600 mm, only 50% of them contribute to annual recruitment each year. Hence, for chondrichthyan species with reproductive cycles of two, three or more years, if maturity ogives are used in population assessments instead of maternity ogives, the models will overestimate recruitment rates.

Extra keywords: asynchrony, Australia, reproduction.


Acknowledgment

We are grateful to Peter Risley, Glenn Richardson and the crew of the fishing vessel ‘Nungurner’ for help in sample collection. This research was supported by an International Postgraduate Research Scholarship and a University of Adelaide Postgraduate Research Scholarship to JMB and an Australian Fisheries Research and Development Corporation grant (FRDC 2002/033) to TIW. BMG was supported by an Australian Research Council QEII Research Fellowship. Funding for the field and laboratory components was provided by Sea World Research and Rescue Foundation, Royal Zoological Society of New South Wales, Nature Foundation SA and Royal Zoological Society of South Australia.


References

Bass A. J. (1973). Analysis and description of variation in the proportional dimensions of Scyliorhinid, Carcharhinid and Sphyrnid sharks. South African Association for Marine Biological Research, Oceanographic Research Institute, Investigational Report No. 32. (Durban, South Africa.)

Bulman, C. , Althaus, F. , He, X. , Bax, N. J. , and Williams, A. (2001). Diets and trophic guilds of demersal fishes of the south-eastern Australian shelf. Marine and Freshwater Research 52, 537–548.
| Crossref | GoogleScholarGoogle Scholar | Conrath C. L. (2004). Reproductive biology. In ‘Elasmobranch Fisheries Management Techniques’. (Eds J. A. Musick and R. Bonfil.) pp. 133–164. (Asia-Pacific Economic Cooperation: Singapore.)

Cortés, E. (1998). Demographic analysis as an aid in shark stock assessment and management. Fisheries Research 39, 199–208.
| Crossref | GoogleScholarGoogle Scholar | FAO (2000). ‘Fisheries Management. 1 Conservation and Management of Sharks.’ (Food and Agriculture Organization of the United Nations: Rome.)

Graham, K. J. (2005). Distribution, population structure and biological aspects of Squalus spp. (Chondrichthyes: Squaliformes) from New South Wales and adjacent Australian waters. Marine and Freshwater Research 56, 405–416.
| Crossref | GoogleScholarGoogle Scholar | Hamlett W. C., and Koob T. J. (1999). Female reproductive system. In ‘Sharks, Skates, and Rays. The Biology of Elasmobranch Fishes’. (Ed. W. C. Hamlett.) pp. 398–443. (Johns Hopkins University Press: Baltimore, MD.)

Hanchet, S. (1988). Reproductive biology of Squalus acanthias from the east coast, South Island, New Zealand. New Zealand Journal of Marine and Freshwater Research 22, 537–549.
Hilton-Taylor C. (2000). ‘2000 IUCN Red List of Threatened Species.’ (IUCN The World Conservation Union: Gland, Switzerland.)

Jones, B. C. , and Geen, G. H. (1977). Reproduction and embryonic development of spiny dogfish (Squalus acanthias) in the Strait of Georgia, British Columbia. Journal of the Fisheries Research Board of Canada 34, 1286–1292.
Last P. R., and Stevens J. D. (1994). ‘Sharks and Rays of Australia.’ (CSIRO Publishing: Melbourne.)

Musick, J. A. , Burgess, G. , Cailliet, G. , Camhi, M. , and Fordham, S. (2000). Management of sharks and their relatives (Elasmobranchii). Fisheries 25, 9–13.
| Crossref | GoogleScholarGoogle Scholar | Ricker W. E. (1979). Growth rates and models. In ‘Fish Physiology 8’. (Eds W. S. Hoar and D. J. Randall.) pp. 677–743. (Academic Press: New York.)

Roa, R. , Ernst, B. , and Tapia, F. (1999). Estimation of size at sexual maturity: an evaluation of analytical and resampling procedures. Fishery Bulletin 97, 570–580.
Walker T. I. (2004). Management measures. In ‘Elasmobranch Fisheries Management Techniques’. (Eds J. A. Musick and R. Bonfil.) pp. 285–321. (Asia-Pacific Economic Cooperation: Singapore.)

Walker T. I. (2005). Reproduction in fisheries science. In ‘Reproductive Biology and Phylogeny of Chondrichthyes: Sharks, Rays and Chimaeras’. (Ed. W. C. Hamlett.) pp. 81–127. (Science Publishers: Enfield, USA.)

Walker, T. I. , Hudson, R. J. , and Gason, A. S. (2005). Catch evaluation of target, by-product, and by-catch species taken by gillnets and longlines in the Shark Fishery of South-eastern Australia. Journal of Northwest Atlantic Fishery Science 35, 505–530.


Watson, G. , and Smale, M. J. (1998). Reproductive biology of shortnose spiny dogfish, Squalus megalops, from the Agulhas Bank, South Africa. Marine and Freshwater Research 49, 695–703.
| Crossref | GoogleScholarGoogle Scholar |

Wourms, J. P. (1977). Reproduction and development in chondrichthyan fishes. American Zoologist 17, 379–410.


Yano, K. (1993). Reproductive biology of the slender smoothhound Gollum attenuatus, collected from New Zealand waters. Environmental Biology of Fishes 38, 59–71.
| Crossref | GoogleScholarGoogle Scholar |

Yano, K. (1995). Reproductive biology of the black dogfish, Centroscyllium fabricii, collected from waters off western Greenland. Journal of the Marine Biological Association of the United Kingdom 75, 285–310.


Yano, K. , and Tanaka, S. (1988). Size at maturity, reproductive cycle, fecundity, and depth segregation of the deep sea squaloid sharks Centroscymnus owstoni and C. coelolepis in Suruga Bay, Japan. Nippon Suisan Gakkai Shi 54, 167–174.