Maturity and batch fecundity of the European hake (<i>Merluccius merluccius</i>, Linnaeus, 1758) in the eastern central Atlantic

Abstract

SUMMARY:The reproductive biology of the European hake (Merluccius merluccius, Linnaeus, 1758) was studied on the eastern central Atlantic Moroccan coast from November 2001 to December 2003. The sex ratio was close to 1:1 for the specimens with a total length of less than 45 cm. European hake spawned all year round, though two spawning peaks were recorded with a certain interannual variability: the first and main peak in winter and a secondary intermittent peak in summer. Length at first maturity was estimated as 28.6 cm and 33.8 cm total length for males and females, respectively. These values are closer to Mediterranean than Atlantic hake values. The mean batch fecundity was 299872 eggs ind -1 . The relative batch fecundity was estimated as 228 eggs per gram of gutted weight. Batch fecundity increased proportionally with fish length and weight. The batch fecundity of European hake in the Moroccan Atlantic area is higher than that in northern Atlantic and northwestern Mediterranean areas.Keywords: Merluccius merluccius, sex ratio, reproductive cycle, length at first maturity, fecundity.RESUMEN: Madurez y fecundidad parcial de la merluza europea (Merluccius Merluccius, Linnaeus, 1758) en el Atlántico Oriental central. -Se ha estudiado la biología reproductiva de la merluza europea (Merluccius merluccius, Linnaeus, 1758) en la zona central del Atlántico Oriental de la costa de Marruecos durante el período de noviembre de 2001 a diciembre de 2003. La proporción sexual fue cercana a 1:1 para los individuos de talla total menor de 45 cm. La merluza europea se reproduce durante todo el año. Se han detectado dos picos de puesta con una cierta variabilidad interanual: el primero y más importante en invierno y otro pico secundario intermitente en verano. La talla de primera madurez se estimó en 28.6 cm y 33.8 cm de longitud total para machos y hembras respectivamente. Estos valores son más cercanos a los observados para la merluza en el Mediterráneo que a los del Atlántico. La fecundidad parcial media fue de 299872 huevos ind -1 . La fecundidad parcial relativa se estimó en 228 huevos por gramo de hembra referido al peso eviscerado. La fecundidad parcial se incrementó proporcionalmente a la longitud y peso del pez. La fecundidad parcial de la merluza europea en el área atlán-tica de Marruecos, muestra valores más altos que en las áreas del Atlántico situadas más al norte y del NW Mediterráneo.Palabras clave: Merluccius merluccius, proporción sexual, ciclo reproductivo, talla de primera madurez, fecundidad. 2011, 447-454, Barcelona (Spain) Scientia Marina75(3) September

Maternal effects on fecundity and egg quality of the Patagonian stock of Argentine Hake (Merluccius hubbsi)

“…The range of fecundity data (40,500-2,550,000 hydrated oocytes) was similar to estimated values from previous studies of Argentine Hake during the same month in other years (Macchi et al, 2004), but the range was much higher than values obtained for other species of Merluccius: Peruvian Hake (M. gayi peruanus) (see Canal, 1989), New Zealand Hake (M. australis) (see Balbontín and Bravo, 1993), European Hake (M. merluccius) (see Murua et al, 2006;Recasens et al, 2008;El Habouz et al, 2011), Cape Hake (M. capensis), and Deepwater Hake (M. paradoxus) (see Osborne et al, 1999). Batch fecundity was infl uenced also by female condition, expressed mainly by liver weight, as was evident from the positive relationship between the number of eggs produced by batch and the HSI.…”

Somatic Condition, Growth and Reproduction of Hake, &lt;i&gt;Merluccius merluccius&lt;/i&gt; L., in the Portuguese Coast

“…In the present study, although this observation is not very clear, an increasing trend of the GSI can be seen along the first semester, while HSI showed a decreasing tendency. These observations are in accordance to the fact that the European hake is reproductively active for almost the entire year and spawning females are found all the year round (Murua and Motos, 2006) [46] and so the annual evolution of the two indexes is not as clear as in species with a shorter spawning season (El Habouz et al, 2011) [44].…”

“…A similar result was observed by Piñeiro and Sainza (2003) [48] in Iberian Atlantic waters corresponding to ICES divisions VIIIc and IXa for the individuals under 45 cm length, but for the bigger classes observations were slightly different, with the males out-numbering the females, after which females predominated and rapidly increased in relative abundance to reach 100% in fish larger than 60 cm. Also El Habouz et al (2011) [44], working with hake from the eastern central Atlantic, refer that the evolution of the sex ratio in the length class interval 17 to 45 cm was close to 1:1 and that only females were found over 45 cm length. Higher number of males for intermediate sizes and higher number of females for larger sizes has been observed by Fariña and Fernández (1986) [64] in the West of Ireland, in the Portuguese coast by Portuguese researchers during five years of surveys (ICES, 1982(ICES, [65], 1983, 1986 [67], 1987 [68], 1988 [69]), as well as in the bay of Biscay by Martin (1991) [70] and [61].…”

Gonad development and reproductive cycle of the white-spotted rabbitfish Siganus canaliculatus (Park, 1797) in Palompon, Leyte, Eastern Visayas, Philippines

“…The length at first maturity (L m50 ) was determined by fitting a logistic curve to the cumulative percentage of mature fish against the length intervals following the equation (Yeates, 1971 as cited by Habouz et al, ):…”

“…the length intervals following the equation (Yeates, 1971 as cited by Habouz et al, 2011): where f(x) is the percentage of mature specimens, M the maximum value of f(x), x the mid-length, a and b are the parameters of the curve, and e is the natural logarithm base. For both sexes, the smallest size observed with mature gonads (histologically) is referred to as the minimum size at maturity.…”