Larval feeding of Scomber japonicus (Pisces: Scombridae) in the Gulf of California and its relation to temperature and chlorophyll satellite data

Feeding habits of Scomber japonicus larvae in the central part of the Gulf of California during April 1984 and 1985 are described and compared. Satellite images of temperature and chlorophyll monthly average showed that the central gulf during April 1984 was relatively warmer but with lower chlorophyll concentration than during April 1985. Feeding incidence was lower in larvae collected in April 1984 than in larvae in April 1985. Prey size consumed was larger in larvae in 1984 than in larvae in 1985. The cladoceran Penilia sp., copepod nauplii, and appendicularians were the dominant prey in the diet of larvae in 1984. In 1985 diatoms and copepod nauplii were the dominant prey. The high incidence of diatoms in S. japonicus larvae collected in 1985, a cold year, corresponded to the high chlorophyll concentration observed by satellite. Diatoms were not an important component in the larval diet in 1984, when the chlorophyll concentration was low. A high incidence of the cladoceran Penilia sp. in the larval gut in 1984 coincided with cladoceran blooms recorded in years affected by El Nino events. Interannual difference in feeding habits of S. japonicus larvae can be associated with changes in environmental conditions, such as temperature and chlorophyll concentration.