Intertidal migration of the four-eyed fish Anableps anableps in North Brazilian mangrove creeks

Abstract

The movement patterns of mangrove fish during tidal cycles are virtually unknown, yet needed to understand fish habitat use. The intertidal migration of the four-eyed fish Anableps anableps L. (Anablepidae, Cyprinodontiformes), a surface-swimming species, was observed along 2 large mangrove-lined creeks in North Brazil. The number, direction and size of the fish crossing fixed line transects were recorded at 5 min intervals using visual surveys during daylight at spring, mid-and neap tide cycles. Migration took place in a surge and was predictably structured and directly related to water level, current speed and direction, and recurred independent of creek and tide. The fish rode the early flood tide upstream towards the creek heads. After the ebb current peak, they returned in a surge along the same pathways. The intertidal distances travelled ranged from 0.7 to > 2 km per tide. Fish density maxima occurred at early flood and late ebb tide, with more fish swimming alone during flood tide and largest group sizes during ebb tides. At neap high tides, fish aggregated in fewer accessible creek heads. When spring tides inundated wider creek areas and made additional creek heads available, maximum fish dispersal occurred. Small fish underwent migrations at shallower water depths than larger fish, thereby optimizing foraging and refuge time. Creek heads were prime feeding grounds, and intertidal creeks were the pathways connecting trophic flows of A. anableps, highlighting that in the management of mangrove ecosystems, complete drainage systems deserve protection. Striking similarities in tidal migrations of resident salt marsh species suggest that equal evolutionary pressures resulted in universal migratory strategies of estuarine resident taxa.

Distribution of fish among Avicennia and Sonneratia microhabitats in a tropical mangrove ecosystem in South China

“…The height and biomass of pneumatophores as well as canopy shade (presented as relative light intensity both inside and outside the vegetated area) were important factors influencing species richness, density, and biomass in our study, suggesting that pneumatophores and trees might provide refuge for fish to escape predation (Laegdsgaard and Johnson 2001). Besides, studies have shown relationships between fish assemblages and water salinity (Barletta et al 2005, Lugendo et al 2007), water temperature (F elix et al 2017), access to creeks (Meynecke et al 2008, Krumme et al 2014, and habitat heterogeneity (F elix et al 2017), etc. At the Avicennia site, structure of pneumatophores had impacts on all measured fish variables, with pneumatophore height showing positive effect but pneumatophore biomass showing negative effect.…”

“…In addition, for the dominant families of Gobiidae and Mugilidae, the density of trees also had significant effects on their amongmicrohabitat variations, and the impacts differed between sites with different mangrove species. Besides, studies have shown relationships between fish assemblages and water salinity (Barletta et al 2005, Lugendo et al 2007), water temperature (F elix et al 2017), access to creeks (Meynecke et al 2008, Krumme et al 2014, and habitat heterogeneity (F elix et al 2017), etc. However, in our study, the water salinity, temperature, or surface elevation did not show significant differences (P > 0.05) among the three microhabitats within the same site due to their short distance between each other (about 20 m).…”

A review of estuarine fish research in South America: what has been achieved and what is the future for sustainability and conservation?

“…In the same system, Krumme et al . () have also studied the intertidal migration patterns of the four‐eyed fish Anableps anableps (L. 1758) and their differential use of various mangrove habitats and Camargo & Isaac () have described the feeding ecology of three species of sciaenids.…”

Ontogenetic resource utilization and migration reconstruction with δ13C values of essential amino acids in the Cynoscion acoupa otolith

“…An occurrence that is not unlikely in macrotidal Amazon estuaries where tides and body size of several fish species were observed to facilitate movement in and out of mangrove creeks (Brenner & Krumme, 2007;Krumme, Calderón, & Echterhoff, 2014). However, some otolith core measurements tended more toward coastal shelf resources and could imply that not all C. acoupa juvenile stages are spent within estuarine mangrove habitats.…”

“…The PCA results depict that the resource utilization of juvenile and adult C. acoupa gradually become distinct and overlap at intermediate life stages, which could indicate that there is a regular movement between estuarine and coastal shelf environments by juveniles. An occurrence that is not unlikely in macrotidal Amazon estuaries where tides and body size of several fish species were observed to facilitate movement in and out of mangrove creeks (Brenner & Krumme, ; Krumme, Calderón, & Echterhoff, ). However, some otolith core measurements tended more toward coastal shelf resources and could imply that not all C. acoupa juvenile stages are spent within estuarine mangrove habitats.…”