Age and growth assessment of western North Atlantic spiny butterfly ray Gymnura altavela (L. 1758) using computed tomography of vertebral centra

Estimating some population parameters and stock assesment of spiny butterfly ray, Gymnura altavela (Linnaeus, 1758) the Levant Basin coast (Northeastern Mediterranean)

“…Parsons et al (2018) examined and found western North Atlantic coasts and found DW =128.54cm for males and DW=217.35cm for females, while this study determined DW=131.25cm for males and DW=136.25cm for females. Upon comparing these values, it was determined that DW of male individuals was smaller than the DW of female individuals.…”

“…In Elasmobranchs, the sexes were different from each other and females were usually bigger. Alkusairy et al 2014; As reported by researchers such as Ozbek et al 2016 andParsons et al 2018, it is obvious that there is sexual dimorphism in individuals. The morphometric analysis of fish is an important aspect in the study of their biology (Qadri et al 2017;Sangün and Güney, 2017).…”

“…This species is known throughout the Turkish seas of the northeastern Mediterranean (Başusta and Erdem, 2000;Yeldan and Avşar, 2007;Yemişken et al 2014;Ozbek et al 2016); its presence has been reported in the Levant Basin, and it has been captured in abundance in the northeastern Mediterranean. Data on the age, growth, feeding, reproduction, and fundamental biological processes of a population of this species from other regions were reported in some research studies (Wigley et al 2003;Filiz and Bilge 2004;Yeldan and Avşar 2007;Başusta et al 2012;Eronat and Ozaydın 2014;Ozbek et al 2016;Parsons et al 2018). The spiny ray is not a target species of commercial fisheries, but caught as bycatch of the demersal trawl, gillnet, trammel net, and bottom longline fisheries (Serena 2005), and data on its biology are inadequate.…”

“…The species obtained were measured for total length (TL), disc length (DL), disc width (DW), nose to eye (NE), mouth width (MW), and nose to mouth (NM) to the nearest 0.5 cm immediately after capture and were weighed (Weight, W: ±1.0 g). Disc width (DW) was used instead of total length (TL) because of the breakage of their tails during hunting during the growth studies made with the ray individuals (Girgin and Basusta 2016;Parsons et al 2018). In this context, DW was used in the study and the tail was not taken into account in the total length measurements.…”

Reproductive biology, length‐weight relationship and diet of co‐occurring butterfly rays, Gymnura poecilura and Gymnura zonura, in Malaysian waters

“…Reproductive biology of gymnurids has been studied in varying degrees since the 19th century until recent years. Nonetheless, information on reproduction had been reported only in some Gymnura species, namely, G. poecilura (James, 1966; Muktha et al ., 2020; Raje & Zacharia, 2009), G. zonura (White & Dharmadi, 2007), Gymnura altavela (Alkusairy et al ., 2014; Paiva et al ., 2018; Taylan et al ., 2019), Gymnura marmorata (Maria et al ., 2019), G. micrura (Parsons, 2017; Raje, 2003; Wood‐Mason & Alcock, 1890; Yokota et al ., 2012; Yokota & Lessa, 2007) and Gymnura australis (Jacobsen et al ., 2009). Generally, gymnurids are viviparous, where a yolk sac initially nourishes embryos, then embryos absorb uterine milk rich in proteins and lipids produced by the mother for embryonic development until birth (Conrath, 2004).…”