Age, growth, and sexual maturity of the yellownose skate Dipturus chilensis in the south‐eastern Pacific

Abstract

The age and growth parameters of Dipturus chilensis were estimated by counting growth rings from thin sections of vertebral centra from 400 fish (246 females and 154 males), ranging from 23 to 124 cm total length (L T ), and backcalculating fish lengths at previous ages. Marginal increment analysis lent support to the hypothesis of annual deposition of band-pairs, which formed during the winter months. The oldest female D. chilensis aged in this study was 21 years and 117 cm L T , whereas the oldest male was 18 years and 93 cm L T . A 4Á7% index of average per cent error (I APE ) suggested that this is a precise method for calculating the age of D. chilensis. Observed L T were lower than backcalculated L T , which implies the influence of Lee's phenomenon. The von Bertalanffy growth equations, based on mean length-at-age data, were estimated as L t ¼ 128Á3 (1 À e À0Á112 (t þ 0Á514) ) for females and L t ¼ 107Á8 (1 À e À0Á134 (t þ 0Á862) ) for males where t is age (years). Growth was significantly different between sexes: females reached a larger adult size. Ages and lengths at 50% maturity were estimated at 14 years of age and 106 cm L T for females and 11 years of age and 86 cm L T for males. At c. 14 years, there was a decline in growth rates in females. The factor most likely responsible for this was sexual maturity, which caused a discontinuity in growth of female fish. These results show that this species is slow-growing, long-lived, relatively large and of delayed maturity, characteristics that make it vulnerable to exploitation.

Assessing the accuracy of using whole and sectioned vertebrae to determine the age of an endemic sisorid catfish, Glyptosternon maculatum, in Tibet, China

“…Although numerous authors have used sectioned vertebral centra of elasmobranchs to estimate age (Cailliet and Goldman 2004; Licandeo et al 2006), the use of sectioned vertebrae has not previously been reported as an approach to aging freshwater fish. Our study indicates that the sectioned vertebrae method affords more accurate age estimation than the whole vertebrae method, especially for older G. maculatum.…”

Skate-ing on thin ice: molecular ecology of longnose skates in the Southeast Pacific Ocean

“…Pequeño, 1989;Lloris & Rucabado, 1991;Pequeño & Lamilla, 1993;Sáez & Lamilla, 1997;Bizikov et al, 2004. Bahamonde et al, 1994;Bahamonde et al, 1996;Mould, 1997;McEachran & Dunn, 1998;Paesch, 1999;Cousseau & Perrotta, 2000Lucifora et al, 2000;Koen Alonso et al, 2001;Gomes & Picado, 2001;Soto & Mincarone, 2001;Lamilla et al, 2002;Last & Yearsley, 2002;Nion et al, 2002;Sánchez & Mabragaña, 2002;Calderón et al, 2003;Lamilla & Sáez, 2003;Meneses & Paesch, 2003;Buren, 2004;García de la Rosa et al, 2004;Massa et al, 2004;Smith et al, 2004;Acuña et al, 2005;Céspedes et al, 2005;Compagno, 2005a, b;Lamilla & Bustamante, 2005;Quiroz & Wiff, 2005;Oddone et al, 2005;Araya & Cubillos, 2006;Lamilla et al, 2006;Licandeo et al, 2006;Concha et al, 2007;Cousseau et al, 2007;Ebert & Bizarro, 2007;Ebert & Compagno, 2007;…”

“…López et al, 1989;Compagno, 1999b;Knoff et al, 2001b;Knoff et al, 2002;López et al, 2002;Oyarzún et al, 2003;Knoff et al, 2004;Cedrola et al, 2005;Compagno, 2005a;Kyne & Simpfendorfer, 2007;Lamilla & Massa, 2007;Menni & Lucifora, 2007;Reyes & Torres-Flores, 2008;Muniz-Pereira et al, 2009;Quiroga et al, 2009;Kyne & Simpfendorfer, 2010;Menni et al, 2010. Stehmann, 1978;Mould, 1997;McEachran & Dunn, 1998;Menni & Stehmann, 2000;Gomes & Picado, 2001;Soto & Mincarone, 2001;Knoff et al, 2001a;Nion et al, 2002;Lamilla & Sáez, 2003;Smith et al, 2004;Céspedes et al, 2005;Compagno, 2005b;Lamilla, 2005;Lamilla & Bustamante, 2005;Lamilla et al, 2006;Licandeo et al, 2006;Bovcon & Cochia, 2007;Ebert & Compagno, 2007;Cousseau et al, 2007;Melo et al, 2007;Arkhipkin et al, 2008;Díaz de Astarloa et al, 2008;D...…”

“…The minimum and maximum sizes reported for Z. chilensis are 156 mm and 1580 mm LT respectively, with females growing to a larger sizes than males (Norman, 1937;Bahamonde, 1953;De Buen, 1959;Leible, 1987;Leible et al, 1990;García de la Rosa, 1998;Cousseau et al, , 2007Gomes & Picado, 2001;Cedrola et al, 2005;Licandeo et al, 2006;Paesch & Oddone, 2008;Estalles et al, 2011;Lamilla et al, 2012a, b;Bustamante et al, 2012). In comparison, D. trachyderma reaches 2540 mm LT for females and 2320 mm LT for males (Leible & Stehmann, 1987;Cousseau et al, , 2007Gomes & Picado, 2001;Cedrola et al, 2005;Lamilla et al, 2012a, b).…”

“…Zearaja chilensis appears to be relatively common at depths of between 14 -100 m depth (Menni & López, 1984;Leible et al, 1990;García de la Rosa, 1998;Concha et al, 2012), is abundant between 150 to 350 m (Menni & Gosztonyi, 1977;Menni & López, 1984;Leible, 1987;Leible et al, 1990;Licandeo et al, 2006;Quiroz et al, 2009;Arkhipkin et al, 2012), but can be found at depths of up to 450 m (Ojeda, 1983;Menni & López, 1984;García de la Rosa, 1998). In contrast, D. trachyderma appears less abundant in shallow waters (a single specimen reported from 20 -22 m in the Beagle Channel (Lloris & Rucabado, 1991), and catches reported from 87 -97 m in San Jorge Gulf (Cedrola et al, 2005), seems most common at 180 m -350 m (Krefft & Stehmann, 1975;Menni & Gosztonyi, 1977;Bizikov et al, 2004;Lamilla et al, 2010;Menni et al, 2010;Arkhipkin et al, 2012), but there are records from 400 -500 m (Leible & Stehmann, 1987;Gomes & Picado, 2001).…”