Shifts of sensory modalities in early life history stage estuarine fishes (Sciaenidae) from the Chesapeake Bay using X-ray micro computed tomography

2016 ◽  
Vol 99 (4) ◽  
pp. 361-375 ◽  
Author(s):  
Alison L. Deary ◽  
Brian Metscher ◽  
Richard W. Brill ◽  
Eric J. Hilton
2017 ◽  
Vol 4 (5) ◽  
pp. 170082 ◽  
Author(s):  
Christopher Doropoulos ◽  
Nicolas R. Evensen ◽  
Luis A. Gómez-Lemos ◽  
Russell C. Babcock

Population growth involves demographic bottlenecks that regulate recruitment success during various early life-history stages. The success of each early life-history stage can vary in response to population density, interacting with intrinsic (e.g. behavioural) and environmental (e.g. competition, predation) factors. Here, we used the common reef-building coral Acropora millepora to investigate how density-dependence influences larval survival and settlement in laboratory experiments that isolated intrinsic effects, and post-settlement survival in a field experiment that examined interactions with environmental factors. Larval survival was exceptionally high (greater than 80%) and density-independent from 2.5 to 12 days following spawning. By contrast, there was a weak positive effect of larval density on settlement, driven by gregarious behaviour at the highest density. When larval supply was saturated, settlement was three times higher in crevices compared with exposed microhabitats, but a negative relationship between settler density and post-settlement survival in crevices and density-independent survival on exposed surfaces resulted in similar recruit densities just one month following settlement. Moreover, a negative relationship was found between turf algae and settler survival in crevices, whereas gregarious settlement improved settler survival on exposed surfaces. Overall, our findings reveal divergent responses by coral larvae and newly settled recruits to density-dependent regulation, mediated by intrinsic and environmental interactions.


2019 ◽  
Vol 76 (1) ◽  
pp. 123-135 ◽  
Author(s):  
Morgan M. Sparks ◽  
Jeffrey A. Falke ◽  
Thomas P. Quinn ◽  
Milo D. Adkison ◽  
Daniel E. Schindler ◽  
...  

We applied an empirical model to predict hatching and emergence timing for 25 western Alaska sockeye salmon (Oncorhynchus nerka) populations in four lake-nursery systems to explore current patterns and potential responses of early life history phenology to warming water temperatures. Given the temperature regimes sockeye salmon experienced during development, we predicted hatching to occur in as few as 58 days to as many as 260 days depending on spawning timing and temperature. For a focal lake spawning population, our climate–lake temperature model predicted a water temperature increase of 0.7 to 1.4 °C from 2015 to 2099 during the incubation period, which translated to a hatching timing that was 16 to 30 days earlier. The most extreme warming scenarios shifted development to approximately 1 week earlier than historical minima and thus climatic warming may lead to only modest shifts in phenology during the early life history stage of this population. The marked variation in the predicted timing of hatching and emergence among populations in close proximity on the landscape may serve to buffer this metapopulation from climate change.


Zootaxa ◽  
2018 ◽  
Vol 4369 (2) ◽  
pp. 270 ◽  
Author(s):  
SEAN GIBBS ◽  
PETER J. HUNDT ◽  
ANDREA NELSON ◽  
JOSHUA P. EGAN ◽  
PRASERT TONGNUNUI ◽  
...  

The combtooth blenny (Blenniidae) genus Omobranchus contains small, cryptobenthic fishes common to nearshore habitats throughout the Indo-West Pacific. Recent molecular systematic studies have resolved Omobranchus as monophyletic but little research has been done to resolve species-level relationships. Herein, phylogenetic analyses of one mitochondrial (CO1) and four nuclear (ENC1, myh6, sreb2, and tbr1) genes provide evidence for the monophyly of Omobranchus and support for the elongatus and banditus species group. Sampling of multiple individuals from widespread species (O. ferox, O. punctatus, and O. elongatus) suggested that the Thai-Malay Peninsula is a phylogeographic break that may be a historic barrier to gene flow. Additionally, common meristics and other morphological characters are used to describe an early life history stage of O. ferox and O. punctatus.  


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