Species‐specific environmental preferences associated with a hump‐shaped diversity/temperature relationship across tropical marine fish assemblages

Abstract

Aim: To identify key environmental factors associated with local fish species richness across a large tropical marine region.Location: Wider Caribbean region.Methods: Species richness estimates were based on a sightings database covering the wider Caribbean region. Environmental variables considered were distance to key habitats, habitat area, temperature, depth, salinity, nutrient concentration, as well as natural and anthropogenic disturbance. We test the significance of associations between these factors and species richness, establish the shape of these relationships and use spatial cross-validation to test the generality of these results.Species-specific environmental associations within these relationships were then tested.Results: Five environmental variables showed significant associations with species richness, but only two, temperature and depth, proved robust to spatial cross-validation. Temperature was the best performing environmental predictor, showing a unimodal relationship with species richness and optimum temperatures consistent across analytical choices and data sets. Relationships between species richness and other environmental factors were also typically unimodal.Variation in species-specific temperature associations was significant within species richness gradients; with a higher number of species associated with optimal temperatures.Main conclusions: Temperature represents the dominant environmental predictor of fish species richness identified by our study, showing a hump-shaped curve, peaking at around 27.4°C. This meant that the warmest sites within our study were not necessarily the most species rich. Variation in species thermal niches may play a key role in driving species richness gradients, with significant general positive trend for fish species to occur in locations exhibiting optimum sea surface temperatures.

Coral reef fish communities, diversity, and their fisheries and biodiversity status in East Africa

“…S1). Relationships between environmental and number of species data were less clear and potentially unimodal (Clauson-Kaas et al 2017). Consequently, I tested number of species for fits to both linear and second-order polynomial relationships but found (with a few exceptions) that linear fits were similar and all explained low (<12.0%) amounts of variation (Table S1).…”

Exploration of Applicability of Diatom Indices to Evaluate Water Ecosystem Quality in Tangwang River in Northeast China

“…This may be because, in the process of community succession, the increase in species diversity is usually a benign adaptation of the ecosystem to mild external disturbance. A large number of studies [32][33][34] have shown that in the process of community succession, species diversity will increase first and then decrease with the increase in external disturbance intensity; that is, a hump-shaped effect. The diatom species diversity in Tangwang River did not show a downward trend with the external disturbance, so it can be inferred that the Tangwang River basin was affected by a low external disturbance intensity, and the overall environmental quality was good and did not reach the critical value of the hump effect.…”

Abundancia, biomasa y estructura de la ictiofauna demersal en el océano Pacífico de Centroamérica, basadas en datos de prospección pesquera realizados a bordo del B/O Miguel Oliver

“…La tendencia asintótica de las dos curvas a partir de 20 sitios de muestreo observado en la Figura 2 evidencia la robustez del método de recolección. Sin embargo, el estudio de patrones regionales de riqueza de especies, a través de ensamblajes, según Clauson-Kaas et al (2017) requiere muestreos largos y estandarizados, por lo cual es recomendable continuar con la recolección de datos, similar a la efectuada en esta oportunidad, en aras de aumentar el conocimiento de la dinámica ecológica y su interacción con el ambiente. Entre las especies más abundantes de peces óseos (Cuadro 1), destacan 3 de aguas profundas de poco valor comercial: D. filamentosa, la cual ha sido reportada como una de las dominantes en otros estudios (Kameya et al 2006); B. atricolor y B. ventralis, ambas pertenecientes a la familia Ipnopidae, reportadas previamente por Cruz-Acevedo et al (2017), quienes estudiaron su distribución en el Pacífico Central junto con otros miembros del género Bathypterois, y H. signifer, que forma parte de la fauna acompañante en la pesca de arrastre de camarón en la costa pacífica de Colombia, pero que no representa una especie objetivo (Puentes et al 2007).…”