Body size at sexual maturity in the eteline snappers Etelis carbunculus and Pristipomoides sieboldii: subregional comparisons between the main and north-western Hawaiian Islands

Abstract

New estimates of median body length at sexual maturity (L50) are presented for females of ehu (Etelis carbunculus) and kalekale (Pristipomoides sieboldii) in the main Hawaiian Islands (MHI); these are compared with published estimates for females of each species in the north-western Hawaiian Islands (NWHI). This case study illustrates the general importance of identifying regional and subregional variations in species’ life histories when estimating parameters for input to stock assessments. L50 values differed somewhat between the two species, but greatly between the MHI and NWHI for each species. Size-standardised ovary weights were greater in the NWHI v. MHI for all-sized fish of both species and nominally greater at larger body sizes among the mature females of both species in the MHI compared with the NWHI. L50 was smaller in the MHI compared with NWHI for females of both species. The mean (±s.e.m.) L50 for female ehu was 23.4±0.3- v. 27.2±1.0-cm fork length (FL) in the MHI v. NWHI respectively. For female kalekale, the respective estimates were 23.8±0.3 and 28.6±0.7cm FL. Possible determinants of these subregional geographic variations in L50, including latitude, productivity and history of extraction by Hawaiian bottomfish fisheries, are discussed.