Use of stochastic models to estimate the growth of the Port Jackson shark, Heterodontus portusjacksoni, off eastern Victoria, Australia

Tovar-Ávila, Javier; Troynikov, Vladimir S.; Walker, Terence I.; Day, Robert W.

doi:10.1016/j.fishres.2008.09.031

Cited by 17 publications

(25 citation statements)

References 27 publications

(43 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The general pattern of growth depicted here is consistent with that observed in the Victorian population of the Port Jackson shark (Tovar-Á vila et al 2009b) and, more generally, in elasmobranch species (Cailliet and Goldman 2004). That is, the growth of the species is characterised by two distinct phases, including rapid growth at birth, which decreases around the time of sexual Table 2).…”

Section: Growth Of the Port Jackson Sharksupporting

confidence: 87%

“…Although species of elasmobranchs are characterised as possessing slow rates of growth, reported values of growth coefficients (k) among species are highly variable, ranging from 0.30 to 1.337 (Cailliet and Goldman 2004). Rates of growth for the Port Jackson shark cannot be compared with other heterodontid species because analogous data do not exist; however, present findings are comparable to those reported for other populations of H. portusjacksoni (Ramos 2007;Tovar-Á vila et al 2009b). …”

Section: Growth Of the Port Jackson Sharksupporting

confidence: 51%

“…For south-eastern Australian populations of Port Jackson sharks, growth curves and length-at-age relationships were calculated on the basis of the available sex-specific VBGF parameters (Ramos 2007;Tovar-Á vila et al 2009b). Sex-specific comparisons of growth among regional populations of Port Jackson sharks were made using ANCOVA of the least-squares linear regression of the length-at-age data.…”

Section: Comparisons Among Regional Populationsmentioning

confidence: 99%

“…The present study, like Tovar-Á vila et al (2009b), employed a sampling methodology that precluded the capture of the largest size cohorts of the respective populations. The size selectivity of the trawl-fishing method employed in the present study failed to capture individuals .1000-mm L T .…”

Section: Growth Of the Port Jackson Sharkmentioning

confidence: 99%

See 3 more Smart Citations

Comparative rates of growth of the Port Jackson shark throughout its southern Australian range

Izzo

Rodda

2012

Mar. Freshwater Res.

View full text Add to dashboard Cite

Abstract. Port Jackson sharks are distributed throughout southern Australia, with evidence suggesting that potential subpopulations exist. If subpopulations are evident, then phenotypic variation among groups should result in differences in life-history parameters. The present study tested for patterns of spatial variability of life-history parameters among regional Port Jackson shark populations. Rates of growth from Port Jackson sharks caught in the gulf waters of South Australia were calculated on the basis of counts of vertebral increments. Growth parameters were obtained by fitting the length-at-age data to von Bertalanffy and Gompertz growth functions. While the derived growth curves fit the length-atage data well (r 2 ranged from 0.87 to 0.91), parameters showed considerable differences between the two functions, with the von Bertalanffy function providing the more realistic estimates of growth (combined sexes: k ¼ 0.081 year À1 , L N ¼ 1232 mm total length and t 0 ¼ À1.937 years). Life-history parameters for South Australian Port Jackson sharks were collated with the available data for the species, facilitating comparisons among regional populations. Growth curves among populations varied significantly; however, considerable overlap in the length ranges of size at birth and sizes at maturity among populations were evident. Overall, the data presented here do not provide definitive support for the presence of subpopulations across the distribution of the Port Jackson shark, suggesting that molecular analysis maybe required to directly test for structuring.

show abstract

Section: Growth Of the Port Jackson Sharksupporting

confidence: 87%

Section: Growth Of the Port Jackson Sharksupporting

confidence: 51%

Section: Comparisons Among Regional Populationsmentioning

confidence: 99%

Section: Growth Of the Port Jackson Sharkmentioning

confidence: 99%

See 2 more Smart Citations

Comparative rates of growth of the Port Jackson shark throughout its southern Australian range

Izzo

Rodda

2012

Mar. Freshwater Res.

View full text Add to dashboard Cite

show abstract

“…Tóvar-Ávila et al [18] considered a reparametrization of the von Bertalanffy growth rate using three different probability distribution functions: Weibull, gamma and log-normal. Such models show an increasing behavior and consider individual variations, but are limited by the fact that they do not account for environmental variations, caused by multiple factors which are not always quantifiable or may even be unknown.…”

mentioning

confidence: 99%

A diffusion process to model generalized von Bertalanffy growth patterns: Fitting to real data

Román-Román

Romero

Torres-Ruiz

2010

Journal of Theoretical Biology

View full text Add to dashboard Cite

The von Bertalanffy growth curve has been commonly used for modeling animal growth (particularly fish). Both deterministic and stochastic models exist in association with this curve, the latter allowing for the inclusion of fluctuations or disturbances that might exist in the system under consideration which are not always quantifiable or may even be unknown. This curve is mainly used for modeling the length variable whereas a generalized version, including a new parameter b ≥ 1, allows for modeling both length and weight for some animal species in both isometric (b = 3) and allometric (b = 3) situations.In this paper a stochastic model related to the generalized von Bertalanffy growth curve is proposed. This model allows to investigate the time evolution of growth variables associated both with individual behaviors and mean population behavior. Also, with the purpose of fitting the above mentioned model to real data and so be able to forecast and analyze particular characteristics, we study the maximum likelihood estimation of the parameters of the model. In addition, and regarding the numerical problems posed by solving the likelihood equations, a strategy is developed for obtaining initial solutions for the usual numerical procedures. Such strategy is validated by means of simulated examples. Finally, an application to real data of mean weight of swordfish is presented.

show abstract

Husbandry conditions of spotted ratfish (Hydrolagus colliei, Chimaeriformes) in aquaria for successful embryonic development and long‐term survival of juveniles

Berio,

Charron,

Dagouret

et al. 2023

Zoo Biology

View full text Add to dashboard Cite

The spotted ratfish Hydrolagus colliei is the most common holocephalan species exhibited in aquaria worldwide for introducing deep‐sea environments and raising awareness of their conservation. However, little is known about the biology of H. colliei. Current practices in aquaria allow long‐term survival of sexually mature H. colliei specimens; however, this species struggles to complete a reproductive cycle in captivity mostly because embryos do not reach the hatchling stage. The aquarists of Planet Ocean Montpellier (POM, France) have bred H. colliei for 15 years and recorded parameters suitable for this species' successful embryonic and post‐embryonic development. POM aquarists now regularly record egg‐laying events of H. colliei and use four tanks to incubate eggs and raise neonates, late hatchlings, early and intermediate juveniles, subadults, and sexually mature specimens. In this work we provide the first long‐term biometric data on H. colliei from the hatchling to the subadult stage. We also report the biotic and abiotic parameters sufficient to breed H. colliei in aquaria. We finally describe the methods used to facilitate individual monitoring of specimens along the ontogeny and several pathologies identified in this species, their putative causes, and the corresponding treatments. This work highlights the importance of ex situ research and points to the valuable outcomes of collaborative efforts between aquaria and academia in deciphering the biology of species whose study in the wild remains challenging.

show abstract

Use of stochastic models to estimate the growth of the Port Jackson shark, Heterodontus portusjacksoni, off eastern Victoria, Australia

Cited by 17 publications

References 27 publications

Comparative rates of growth of the Port Jackson shark throughout its southern Australian range

Comparative rates of growth of the Port Jackson shark throughout its southern Australian range

A diffusion process to model generalized von Bertalanffy growth patterns: Fitting to real data

Husbandry conditions of spotted ratfish (Hydrolagus colliei, Chimaeriformes) in aquaria for successful embryonic development and long‐term survival of juveniles

Contact Info

Product

Resources

About