Spatial patterns of zooplanktivore Chirostoma species (Atherinopsidae) during water-level fluctuation in the shallow tropical Lake Chapala, Mexico: seasonal and interannual analysis

Abstract

This study addresses the influence of water-level fluctuations on fish distribution at two temporal scales: seasonal (dry and rainy) and interannual (low and high volume conditions). The analysis of abundance relationships among three zooplanktivore Chirostoma species at fifteen sites in Lake Chapala, Mexico, revealed the significant influence of contrasting conditions (P=0.0002). Seasonally, segregation was more related to species dominance in the dry season and exclusively related to environmental characteristics in the rainy season. Interanually, biotic influence occurred in the shallowest and the deepest episodes of the lake. Environmental characteristics influenced species distribution when the lake reached 25% of its volume. Site, depth, temperature, and salinity were the leading factors influencing fish distribution. These results emphasize the necessity to implement different management strategies according to lake volume, particularly when a critical threshold is reached.El presente estudio describe la influencia que tiene la fluctuación del nivel del agua en la distribución de los peces a dos diferentes escalas: estacional (estiaje y lluvias) e interanual (condiciones de bajo y alto volumen). El análisis de las relaciones de abundancia entre tres especies zooplanctófagas de Chirostoma en quince sitios del Lago de Chapala, México, reveló una influencia estadísticamente significativa en las condiciones contrastantes (P=0.0002). Estacionalmente, la segregación estuvo más relacionada a la dominancia de las especies en la época de estiaje y exclusivamente relacionada a las características ambientales en la época de lluvias. Interanualmente, la influencia biótica se presenta en los episodios más someros y más profundos del lago. Las características ambientales influenciaron la distribución de las especies cuando el lago alcanzó el 25% de su volumen. El sitio geográfico, profundidad, temperatura y salinidad fueron los principales factores que influenciaron la distribución de los peces. Estos resultados enfatizan la necesidad de implementar diferentes estrategias de manejo de acuerdo al volumen del lago, particularmente cuando se alcanza un umbral crítico.

Stable isotope evidence for trophic overlap of sympatric Mexican Lake Chapala silversides (Teleostei: Atherinopsidae: Chirostoma spp.)

“…Lower δ 15 N values for C. jordani could be due to these dietary differences. Chirostoma jordani is also known to occupy shallower areas close to the lakeshore than other species and dominates in the Lerma River inflow zone (Moncayo-Estrada et al, 2011a). Figure 2 suggests that C. sphyraena could have a relatively high trophic position among analyzed Chirostoma.…”

“…It also suggests that potential competition could be occurring among Chirostoma, C. encaustus, and non-native bluegill. However, competition could be reduced by differences in prey availability (i.e., zooplankton assemblage and densities) and predator species differential distribution in the lake (i.e., C. labarcae vs. C. jordani) (Welker et al, 1994;Pangle et al, 2007;Moncayo-Estrada et al, 2011a). Goodea atripinnis and Oreochromis sp., fishes located relatively low in the Lake Chapala food web, are known omnivores (Bruton & Boltt, 1975;Miller et al, 2005).…”

“…Evidence from gut content analyses has uncovered differences among species (Moncayo-Estrada et al, 2010, 2011b. In some cases, such differences have been attributed to changing Lake Chapala water levels (Moncayo-Estrada et al, 2011a), but other, fine scale studies have suggested preference of a species for a given zooplanktonic group (i.e., diet dominance of cladocerans vs. calanoid or cyclopoid copepods) (MoncayoEstrada et al, 2007). While charales and pescados blancos did separate in isotopic space, we were generally unable to differentiate species of Chirostoma based on stable isotope data.…”

Getting in shape: habitat-based morphological divergence for two sympatric fishes

“…These traits have been attributed to differences in prey choice and feeding orientation within and between many fish species (Gatz, ; Winemiller, ; Hendry et al ., ; Russo et al ., ). Chirostoma jordani is primarily a zooplanktivorous species (Moncayo‐Estrada, Lind & Escalera‐Gallardo, ; Moncayo‐Estrada, Escalera‐Gallardo & Lind, ), whereas G. atripinnis is a filter feeder with a diet of zooplankton and green algae (Miller et al ., ). Both species exhibit more of an upturned mouth in lentic environments (Figs , ) and a more superior mouth has been shown to a trait common in surface feeding fishes (Winemiller, , ).…”

Length‐weight relationships of six fish species of tropical lake, Mexico

“…All silverside species had an isometric growth ( b = 3), their body increased proportionally in length and weight. The monthly variations of the growth coefficient b observed in some silverside species could be related to the sample size, feeding, maturity state, environmental conditions and the rapid growth in the early stages of life (Moncayo‐Estrada, Escalera‐Gallardo, & Lind, 2011; Torres‐Orozco & Pérez‐Hernández, 2011). We must consider also differential shrinkage during the processes of specimen fixation and preservation (Silva, Corrêa, Oliveira, & Vieira, 2019).…”