Larval fish assemblages in nearshore waters of southeast Gulf of California: vertical and temporal patterns

Abstract

The influence of salinity and temperature on larval fish assemblages, as well as, temporal and vertical patterns on larval fish assemblages off the inlet of the Presidio River, southeast coast of the Gulf of California were evaluated. Samplings for ichthyoplankton and environmental parameter measurements were carried out at three depths, in five sampling sites, during September and December 1994, and April and June 1995. Anchovies and herrings (Clupeiformes) were the most abundant larval fish accounting for 77% of the total abundance. A significant relationship between salinity and the abundance of larval herrings (Opisthonema medirastre and O. dovii) and between the water temperature and the abundance of the weakfish (Cynoscion reticulatus) was found. Anchovies (Anchoa lucida, A. walkeri, and A. nasus) were present in all sampled months, while O. medirastre and O. dovii occurred in December and June, and C. reticulatus in September. Larvae of pelagic fish were more abundant near the surface, while larvae of demersal fish were more abundant near the bottom. The present study, by emphasising the importance of considering temporal and vertical changes in larval fish assemblages in coastal environments with ecological and economic importance, will be useful for designing more efficient sampling programs.

Early life history of the middling thread herring (Opisthonema medirastre) in the central Galápagos Islands

“…(2007), 25.8 ± 4.0 °C in Amezcua et al . (2020), 26–28 °C during February 2017 in the current study, 18–23°C in Ortega (1995), and 23–25 °C during May 2017 and 25–28 °C during May 2017 and February 2018 in the current study. The pattern seen during the wet/warm season of neutral years is therefore likely due to a combination of oceanographic conditions such as circulation, water stratification and food availability, and not just water temperature, that may be favourable to the foraging, reproduction, larval retention and survival, etc ., of this species.…”

“…The extremes of this cycle are the El Niño (positive) and La Niña (negative conditions). The presence of large numbers of Opisthonema larvae and juveniles during neutral wet seasons in this and previous studies (Luzuriaga de Cruz et al ., 2007; Amezcua et al ., 2020) as opposed to low numbers caught in years with positive or negative conditions (Current study: Feb 2018, Ortega, 1995) appears to be a recurrent pattern. Sea‐surface temperature alone does not seem to be the factor driving these differences as water temperatures in these studies were similar, 22–31 °C in Luzuriaga de Cruz et al .…”

“…7 years (Dawson, 1986; Luzuriaga de Cruz et al ., 2007; Rodríguez et al ., 1989). The larvae are mostly found very close to shore and throughout the water column (Amezcua et al ., 2020; Luzuriaga de Cruz et al ., 2007; Ortega, 1995).…”

“…Although MTH has been poorly studied, it is thought to have a mostly coastal distribution (out to 20 nm), reproduce year-round with peaks during warmer seasons and live up to c. 7 years (Dawson, 1986;Luzuriaga de Cruz et al, 2007;Rodríguez et al, 1989). The larvae are mostly found very close to shore and throughout the water column (Amezcua et al, 2020;Luzuriaga de Cruz et al, 2007;Ortega, 1995).…”