Age, growth and age at sexual maturity of fan rayPlatyrhina sinensis(Batoidea: Platyrhinidae) in Ariake Bay, Japan

Abstract

Age, growth and sexual maturity of the fan ray Platyrhina sinensis in Ariake Bay, Japan were determined from specimens collected from May 2002 to September 2006. Age determination was conducted by vertebral centrum analysis using soft X-radiography. Annual band pair deposition was determined by marginal increment and edge analyses. The von Bertalanffy growth model best described the overall pattern of growth for both males and females (males Lϰ = 455.2, k = 0.56, t0 = -1.09; females Lϰ = 555.8, k = 0.28, t0 = -1.77; Lϰ is the theoretical asymptotic total length in mm, k is the growth rate coefficient and t0 is the theoretical time at zero length). Parameter estimates suggest that females attain a larger asymptotic total length and grow more slowly than males. The observed maximum ages were 5 years for males and 12 years for females. Age at 50% sexual maturity was 2.1 years for males and 2.9 years for females. The results indicate that this species is relatively fast-growing, short-lived and early maturing compared with many batoid species.

Age and growth of Neotrygon picta, Neotrygon annotata and Neotrygon kuhlii from north‐east Australia, with notes on their reproductive biology

“…Vertebrae were prepared and examined, with age estimates based on three counts (Smith et al , 2007; Kume et al , 2008). In each instance, band pairs of one sectioned centrum were counted and cross‐referenced with that of the two adjacent centra (White et al , 2001; Pierce & Bennett, 2009).…”

Reproductive biology of the guitarfish Rhinobatos hynnicephalus (Batoidea: Rhinobatidae) in Ariake Bay, Japan

“…Of the 22 elasmobranch species identified in the bay since November 2001, 18 have been confirmed to be batoid species, indicating high diversity of batoid fish in the bay (Kume et al 2008;Yamaguchi and Kume 2009). In experimental trawl surveys, conducted regularly since November 2001 in the central region of Ariake Bay, batoid species occurred in all the trials, where they comprised a maximum of 64.3% of the total catch by weight (Yamaguchi and Kume 2009).…”

“…In experimental trawl surveys, conducted regularly since November 2001 in the central region of Ariake Bay, batoid species occurred in all the trials, where they comprised a maximum of 64.3% of the total catch by weight (Yamaguchi and Kume 2009). However, relatively few ecological studies have been conducted on the batoid species in Ariake Bay (Yamaguchi et al 2005;Kume et al 2008;Yamaguchi and Kume 2009). …”

Reproductive biology of the fanray, Platyrhina sinensis (Batoidea: Platyrhinidae) in Ariake Bay, Japan

“…There has been only one study concerning age, growth and age at sexual maturity for this species from Ariake Bay (Kume et al 2008). The objective of the present study was to examine the size at sexual maturity, reproductive cycle and fecundity of P. sinensis from Ariake Bay.…”