Effects of temperature and latitude on larval traits of two estuarine fishes in differing estuary types

Abstract

Variations in abiotic conditions across large latitudinal gradients can strongly influence the early life history of coastal marine organisms. We investigated the effects of temperature and latitude on the larval traits of 2 estuarine fish species. The arrow goby Clevelandia ios and the endangered tidewater goby Eucyclogobius newberryi were studied in 18 estuaries along the coast of California, spanning ~8 degrees of latitude. These 2 species were selected because of their dissimilar preferences for estuary type: the arrow goby prefers cooler, fully tidal systems, whereas the tidewater goby prefers warmer lagoons that experience some degree of seasonal isolation from the ocean. Recently settled individuals were collected from July to October 2011, and temperatures within each estuary were recorded to determine how temperature affected larval duration, settlement, and growth rates. Temperatures were more variable among estuaries inhabited by the tidewater goby (10°C range) than among those inhabited by the arrow goby (5°C range). Larval traits of both species differed among sites, but more so for the tidewater goby, a difference that was tied to the greater differences in temperatures among sites in the seasonally closed estuaries it inhabited. In both species, fish that experienced warmer temperatures had shorter larval durations and faster growth rates and were smaller at settlement. Since the length of the larval period has been related to survival and dispersal distance, future variations in temperature due to climate change could have predictable influences on population density and connectivity in estuarine species.

How sea level change mediates genetic divergence in coastal species across regions with varying tectonic and sediment processes

“…structure results (Figure ) show that refugia along steep coastlines generate distinct groups more often than refugia along broad coasts (Figure , Tables , ). Populations along broad coasts have higher allelic richness and broad‐coast refugia probably had greater genetic connectivity during lowstand due to larger size, greater proximity and/or greater openness to the ocean (Spies & Steele, ), which can facilitate connectivity.…”

Survival, growth and stress response of juvenile tidewater goby,Eucyclogobius newberryi, to interspecific competition for food

“…Given that the species has a short lifespan in the wild and that estuarine habitat can be dynamic and variable, quick growth and high reproductive output are important to the local abundance of the species and are factors in maintaining the resilience of a population ( Lafferty et al ., 1999a , b ; US Fish and Wildlife Service, 2005 ). After a brief pelagic larval stage, the E. newberryi juvenile stage may only last a few weeks, when the fish is 9.8–24.8 mm standard length (SL), and ends when sexual maturity is achieved (potentially starting at 25 mm SL for males and 27 mm SL for females; Swift et al ., 1989 ; Swenson, 1999 ; Spies and Steele, 2016 ). Fecundity is positively associated with size in E. newberryi , and for a species that typically lives only a year in the wild, a delay or impairment in growth during the juvenile stage that results in smaller females or delayed sexual maturation could compromise the quantity of young produced and the number of times that reproduction can occur ( Swift et al ., 1989 ; Swenson, 1993 , 1999 ; McGourty et al ., 2008 ).…”

Correlates of population genetic differentiation in marine and terrestrial environments

“…The four solid‐filled marine points represent SDC species contrasts from Dawson et al. () (using F and PD ; Spies & Steele, ) and Dawson et al. () (using F , N c , and PD ) to calculate Nm contrasts.…”

“…Points in the positive quadrant indicate a positive relationship between contrasts in dispersal potential and contrasts in population genetic structure and the closer a point is to the dashed grey line-which represents the relationship P Nm 1 / P Nm 2 ≈ E Nm 1 / E Nm 2 -the more closely that SDC pair matches the theoretical expectation that differences in dispersal potential lead to corresponding differences in population genetic structure. The four solid-filled marine points represent SDC species contrasts from Dawson et al (2002) (using F and PD;Spies & Steele, 2016) and Dawson et al (2014) (using F, N c , and PD) to calculate Nm contrasts. Figure S2.1 provides a key to identifying which datapoints correspond with each SDC pair shown in Figure 3 and Table 1 and Table S1 in Supporting Information Appendix S2.…”