Reproduction, growth and mortality of the exploited sillaginid,Sillago ciliataCuvier, 1829

Abstract

Summary The goal of this study was to examine the age and size composition, growth, reproductive biology and mortality of Sillago ciliata Cuvier, 1829 in one of the largest estuarine commercial fisheries in south‐eastern Australia. The study also aimed to present a qualitative comparison of latitudinal variations in some of these characteristics along the eastern Australian coastline. The sampled population contained fish aged up to 10 years with a maximum size of 39.2 cm fork length (LF), and was dominated by 1–5 year olds. Sexual divergence in both the age and size structure of the population was recorded. Female S. ciliata grew slightly faster and attained a greater maximum size (L∞ = 33.79 cm LF, k = 0.50 year−1 and t0 = −0.57 years) than males (L∞ = 29.73 cm LF, k = 0.49 year−1 and t0 = −0.67 years). Females also matured at a significantly larger size (19.13 cm) and older age (1.63 years) than males (size: 17.07 cm, age: 1.10 years). Reproductive activity was highest between September and March. There were no differences between males and females in terms of mortality rate; the estimated total population, natural and fishing mortality rates were Z = 0.64, M = 0.42 and F = 0.22, respectively. Although these mortality rates suggest that S. ciliata in the Clarence River are relatively resilient to current rates of exploitation, regular monitoring of their commercial and recreational catch as well as their population structure is recommended in order to maintain sustainable fisheries. Potential latitudinal shifts in the spawning period, age structure and growth of S. ciliata along eastern Australia were also revealed.

Length- and age-based demographics of exploited populations of stout whiting,Sillago robustaStead, 1908

“…Many of the 31 species of the teleost family Sillaginidae are exploited in commercial, recreational and artisanal fisheries (Gray & Kennelly, ; Henry & Lyle, ; McKay, ), with several subject to substantial demersal trawl‐based fisheries (Graham, Broadhurst, & Millar, ; McKay, ; Panhwar, Liu, Khan, & Siddiqui, ). Important age, growth and longevity data are available for several harvested species, including the oriental whiting Sillago aeolus Jordan & Evermann, 1902 (Rahman & Tachihara, ), Japanese whiting S. japonica Temminck & Schlegel, 1843 (Yokota, Kitada, & Watanabe, ), silver whiting S. sihama (Forsskål, 1775) (Reddy & Neelakantan, ), yellowfin whiting S. schomburgkii Peters, 1865 (Hyndes & Potter, ), school whiting S. bassensis Cuvier, 1829 (Hyndes & Potter, ), trawl whiting S. flindersi McKay, 1985 (Gray, Barnes, Ochwada‐Doyle et al., ), trumpeter whiting S. maculata Quoy & Gaimard, 1824 (Kendall & Gray, ), sand whiting S. ciliata Cuvier, 1829 (Ochwada‐Doyle, Stocks, Barnes, & Gray, ), and spotted whiting Sillaginodes punctata (Cuvier, 1829) (Fowler, McLeay, & Short, ; Hyndes, Platell, Potter, & Lenanton, ). These studies show that, in general, sillaginids grow quickly, have longevities between 4 and 14 years, and have populations dominated by a few young age‐classes (Kendall & Gray, ).…”

“…& Evermann, 1902 (Rahman & Tachihara, 2005), Japanese whiting S. japonica Temminck & Schlegel, 1843 (Yokota, Kitada, & Watanabe, 1999), silver whiting S. sihama (Forsskål, 1775) (Reddy & Neelakantan, 1992), yellowfin whiting S. schomburgkii Peters, 1865 (Hyndes & Potter, 1997), school whiting S. bassensis Cuvier, 1829 , trawl whiting S. flindersi McKay, 1985 , trumpeter whiting S. maculata Quoy & Gaimard, 1824 (Kendall & Gray, 2009), sand whiting S. ciliata Cuvier, 1829 (Ochwada-Doyle, Stocks, Barnes, & Gray, 2014), and spotted whiting Sillaginodes punctata (Cuvier, 1829) (Fowler, McLeay, & Short, 2000;Hyndes, Platell, Potter, & Lenanton, 1998). These studies show that, in general, sillaginids grow quickly, have longevities between 4 and 14 years, and have populations dominated by a few young ageclasses (Kendall & Gray, 2009).…”

Tidal migrations of juvenile Sillago spp. in a subtropical intertidal nursery seascape

“…All these factors, and probably more, are likely to influence how juvenile fish utilise their intertidal nursery seascape and speak to the dynamic and complex nature of nursery seascapes. Temporally, differences are likely to come about because of the growth and development of the juvenile cohort, which typically has peak recruitment into intertidal areas around October and November, but continues to March (Chargulaf et al 2011;Ochwada-Doyle et al 2014).…”

Reproductive pattern and population dynamics of commercial red swamp crayfish (Procambarus clarkii) from China: implications for sustainable aquaculture management

“…In fish or crayfish population dynamics studies, understanding of population parameters such as growth (growth coefficient K and growth parameter index Ø ′), mortalities (total mortality rate Z , natural mortality rate M , and fishing mortality rate F ) has important implications for population assessment (Rochet et al, 2000). Estimates of these parameters provide fundamental information for predicting population growth and developing sustainable exploitation strategies (Nurul Amin, Zafar & Halim, 2008; Ochwada-Doyle et al., 2014).…”