SynopsisTen early premetamorphic bonefish (AZbufa sp.) leptocephali were collected in MOCNESS plankton tows in the Guaymas Basin area of the Gulf of California from 27 July-l August, 1985. Initial captures of five larvae showed that these were found only in surface waters (O-100 m) at temperatures of 15-29" C. A shallow tow made from 200 m to the surface resulted in the capture of five additional larvae that were distributed in the upper 50 m of the water column at temperatures of 21-29°C. Both pre-flexion larvae (c17.0 mm notochord length, NL,) and larvae with flexed notochords were captured. The size range was from 12.Omm NL to 27.0mm st.andard length. Drawings of representative larvae are given. This is apparently the first report of premetamorphic bonefish larvae for the Gulf, although metamorphic larvae have been known to be abundant in coastal areas of this region for almost 100 years. Distribution records for metamorphic larvae are reviewed. This, together with observations on seasonal distribution of ripe adults in coastal waters near Guaymas, Sonora, Mexico, has allowed us to speculate on various aspects of life history. Our data suggest that spawning occurs during late spring and summer and that early development takes place offshore. The premetamorphic interval is postulated to last approximately 6-7 months. Larvae then return to coastal areas during the winter and spring to complete metamorphosis.
Se examinaron contenidos estomacales y aparatos filtradores de ejemplares adultos de sardina monterrey (Sardinops caeruleus) y sardina crinuda (Opisthonema libertate), recolectados en el Golfo de California, con el fin de describir su alimentación. Ambas especies son filtradores omnívoros que presentan un espectro trófico amplio, mostrando índices de selectividad elevados hacia algunos grupos planctónicos, siendo la frecuencia de éstos directamente proporcional a su abundancia en el plancton. El traslapo por alimento, tanto en número como en volumen, fue alto entre las dos especies. Los adultos de ambas especies presentan espacios interbranquiespinales muy reducidos, en comparación con los individuos de menor tamaño, siendo éstos de 90.20 a 96.50 um para la sardina monterrey y de 60.60 a 62.50 um para la sardina crinuda. Esta morfología del aparato filtrador se refleja en un mayor consumo de microplancton durante las fases adultas. Los taxa más importantes en la dieta de ambas especies fueron Planktoniella sol y Coscinodiscus sp. (Bacillariophyceae), Peridinium sp. (Dinophyceae), con tamaños que variaron entre 75 y 150 um, así como Calanus sp. (Copepoda), con tallas variables entre 700 y 1,500 um.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.