Life History Of Marine Fish Research Articles

A Novel Association between Larval and Juvenile Erythrocles schlegelii (Teleostei: Emmelichthyidae) and Pelagic Tunicates

We describe the first documented associations between an emmelichthyid and a pelagic tunicate. An in situ observation of larval and juvenile Japanese Rubyfish, Erythrocles schlegelii (Emmelichthyidae) was made during blackwater scuba dives in the epipelagic waters off the coast of the Philippines. The fish were in close association with the pelagic salp Pegea confoederata (Thaliacea; Salpidae), either drifting alongside a colony of salps or residing inside individual salp cavities. Our results describe and illustrate this behavior, highlighting a previously undocumented family of fishes that associates with pelagic gelatinous invertebrates. This finding also demonstrates the importance of community science to further our understanding of the early life history of marine fishes.

Mismatch between shape changes, early growth, and condition for a temperate reef fish from an oceanic island

Settlement is a key process in the life history of marine fish, when shape and ecological changes occur during the transition from a pelagic larva to a benthic juvenile. We studied the covariation of shape changes, condition, and pre- and post-settlement growth of settlers (17–30 mm) of the wrasse, Pseudolabrus gayi, from the Robinson Crusoe island, south-eastern Pacific. Specimens were collected during late March 2018 from four locations at 20 m depth and from a large, natural intertidal pool. The morphospace and the allometry were characterised by landmark-based geometric morphometrics, size and growth were estimated using sagittae otolith microstructure analysis, and condition was determined using the Fulton index. The settler’s phenotype varied from a robust shape with ventrally oriented mouth opening, to slender specimens with frontally oriented mouth, with similar body morphospace among sites. The mean pelagic larval duration was 44.8 ± 4.6 days, settling at 19 ± 2 mm SL. The mean post-settlement growth rate was low (0.09 mm day−1), showing low static allometry (3%). Differences among locations occurred in terms of settler’s condition and growth prior and after settlement, suggesting effects of the microhabitat and potential predators. Therefore, the variability in the settler’s morphospace was decoupled of pre- and post-settlement growth and condition during the transition from pelagic to benthic habitat. Finally, this study highlights the dynamic nature of the settlement–transition period for a temperate reef fish in a period when phenotype variations in body shape and early life-history traits vary asynchronously.

Live fast, die young: Behavioural and physiological impacts of light pollution on a marine fish during larval recruitment

Artificial light at night (ALAN) is a recently acknowledged form of anthropogenic pollution of growing concern to the biology and ecology of exposed organisms. Though ALAN can have detrimental effects on physiology and behaviour, we have little understanding of how marine organisms in coastal areas may be impacted. Here, we investigated the effects of ALAN exposure on coral reef fish larvae during the critical recruitment stage, encompassing settlement, metamorphosis, and post-settlement survival. We found that larvae avoided illuminated settlement habitats, however those living under ALAN conditions for 10 days post-settlement experienced changes in swimming behaviour and higher susceptibility to nocturnal predation. Although ALAN-exposed fish grew faster and heavier than control fish, they also experienced significantly higher mortality rates by the end of the experimental period. This is the first study on the ecological impacts of ALAN during the early life history of marine fish.

Combined effects of ocean acidification and crude oil pollution on tissue damage and lipid metabolism in embryo-larval development of marine medaka (Oryzias melastigma).

Ocean acidification (OA) and crude oil pollution have been highlighted as some of the most pervasive anthropogenic influences on the ocean.In marine teleosts, early life-history stages are particularly vulnerable to disturbance by CO2-driven acidification as they lack pH-mediated intracellular regulation. Embryos exposed to trace levels of crude oil constituents dissolved in water exhibit a common syndrome of developmental abnormalities. So far, little is known about the combined effects of OA and crude oil on the early life history of marine fish. Eggs and larvae of the marine medaka (Oryzias melastigma) were treated with CO2 (1080μatm atmospheric CO2), the water-soluble fraction (WSF) of crude oil (500μg/L) and a CO2 (1080μatm atmospheric CO2)/WSF (500μg/L) mixture within 4h after oviposition. Isolated and combined OA/WSF had no detectable effect on embryonic duration, egg survival rate and size at hatching. Histopathological anomalies of tissue and lipid metabolic disorder were significant when CO2 or WSF was given alone at 30days of age. Combination of CO2 and WSF enhanced their toxicity compared to their separate administration. Since the early life-history stage of marine fish is thought to be impacted more heavily by increasing CO2 partial pressure (pCO2) levels and crude oil pollution, OA and crude oil pollution have the potential to act as an additional source of natural mortality.

Bruce S. Miller and Arthur W. Kendall, Jr.: Review of “Early life history of marine fishes”

Bruce S. Miller and Arthur W. Kendall, Jr.: Review of “Early life history of marine fishes”

Early life history of marine fishes

The life cycles of fishes are complex and varied, and knowledge of the early life stages is important for understanding the biology, ecology, and evolution of fishes. In Early Life History of Marine Fishes, Bruce S. Miller and Arthur W. Kendall Jr., bring together in a single reference much of the research available and its application to fishery science - knowledge increasingly important because, for most fishes, adult populations are determined at the earliest stages of life. Clear and well written, this book offers expert guidance on how to collect and analyze larval fish data and on how this information is interpreted by applied fish biologists and fisheries managers.

Diverting the Colorado River leads to a dramatic life history shift in an endangered marine fish

Diversion of river water has diminished freshwater flow into many estuaries worldwide, yet the effects of these diversions on marine fisheries, many of which depend on estuaries, are largely unexplored. We document the impact of diverting Colorado River flow from the Gulf of California on the life history of a now-endangered marine fish (Totoaba macdonaldi, Sciaenidae). Growth increments in prehistoric (1000–5000 ybp) otoliths document that pre-dam juveniles grew twice as fast and matured 1–5 years earlier than post-dam fish. Oxygen isotopes link these changes to elimination of estuarine habitat. This study provides evidence that river diversion can have a dramatic effect on life history of marine fishes by slowing growth during the juvenile stage, thus delaying maturation. These findings also provide valuable insight into the relative influence of habitat alteration versus fishing pressure on marine fishes.

A Coupled Asymmetrical Multiple Opening Closing Net with Environmental Sampling System

Recruitment levels of fishes are potentially related to the abundance of larval fishes and their food source. A system that could allow for the concurrent investigation of fine-scale distribution of fish larvae and their potential prey could add significantly to the understanding of the early life history of marine fishes. A coupled Multiple Opening Closing Net and Environmental Sensing System (MOCNESS) that combines two sub-systems (1 m2 and 4 m2 net sets) working in synchronization was designed to answer these questions. The mesh size was different on each set of nets allowing the collection of a broad size range of organisms while optimizing the catch of larger fish larvae and eliminating unnecessary large samples of zooplankton. Moreover, the system eliminated the need to deploy separate MOCNESS using different mesh sizes, thus reducing ship time costs, and avoiding any aliasing associated with trying to sample the same water mass with separate nets fished sequentially. The system has been used at sea under varying weather conditions onboard the R/V F. G. Walton Smith and sampled adequately.

Passive and active behavioural contributions to patchiness and spatial pattern during the early life history of marine fishes

Multiple ichthyoplankton surveys of Placentia Bay, Newfoundland during the spring and summers of 1997 and 1998 indicated that both passive and active processes contribute to spatial pattern in pelagic eggs and larval fish. Distribution patterns of pelagic eggs and early larvae in coastal Newfoundland waters were consistent with passive drift during development, but older larvae were associated with areas of high production. Recently hatched larvae from pelagic spawners decreased in size throughout the spawning season, reflecting seasonal decreases in egg diameter. Larvae from demersal eggs increased in size over the same time period, possibly reflecting retention and growth. Lloyd's index of patchiness calculated for pelagic eggs generally increased during development, suggesting passive retention. Patchiness decreased after hatch, then increased at approximately 10 mm. We hypothesize that the observed spatial patterns in older larvae, seasonal size increases in larvae from demersal eggs, and ontogenetic changes in patchiness reflect active processes. Predator patchiness, ontogenetic changes in spatial patterns, and published larval consumption rates support the hypothesis that mortality did not generate this pattern. Furthermore, mean crowding of capelin larvae by potential prey increased with development. Increases in patchiness during late larval development coincided with the size at which swimming ability was predicted to exceed ambient flow. This pattern suggests that larger larvae may actively contribute to their spatial distribution. We conclude that swimming ability and behaviour become increasingly important in determining spatial distribution patterns as pelagic larvae develop.

Scale-dependent variations in the precision of larval fish abundance estimates: a study of Sebastes sp. on Flemish Cap

We test the assumptions of synopticity over a 6-d sampling period and homogeneity within a 40 times 40 km stratum by investigating the effect of sampling scale, or station spacing, on the precision (i.e., variance) of abundance estimates of larval redfish (Sebastes sp.). We contrast the results obtained for larval redfish with observations of scale-dependent variability in temperature, salinity, chlorophyll, and zooplankton, which have been shown to be interrelated in other systems. In contrast with previous studies, our results show that the patterns of variance in temperature, salinity, chlorophyll, and zooplankton are not scale dependent. Although the assumption of synopticity cannot be rejected, our results show that the variance in abundance of larval redfish is scale dependent and that it is much greater than the variances of the other variables considered. The contrasting pattern may be due to differences in the relative importance of physical and biological processes during the very early life history of marine fish. We suggest that sampling programs must be preceded by pilot studies designed to determine the effort required to obtain the most precise estimates of abundance given the limitations caused by the underlying sampling variability and the influence of physical processes.

Electron microprobe analysis of juvenile walleye pollock, Theragra chalcogramma, otoliths from Alaska: a pilot stock separation study

The incorporation of dissolved oceanic constituents in the otoliths of fish has potential as a chemical tracer for reconstructing the early life history of marine fish. Wavelength dispersive spectrometers on an electron microprobe were used to measure Na, Mg, P, S, Cl, K, Ca, and Sr concentrations on the outer margins of 57 juvenile walleye pollock, Theragra chalcogramma, otoliths from five locations in the Gulf of Alaska and Bering Sea. Discriminant analyses that used various combinations of Na, P, K, Sr, and fish standard length and/or age showed that 60–80% of the samples could be assigned to the correct capture locality. While the concentrations of some of the measured elements correlated with standard length or age of the fish, there are measurable differences among localities when concentrations are length or age corrected, mainly due to differences in Na and K concentrations. Elemental composition of otoliths potentially could be used to assign fish from a mixed stock fishery to original stocks, information that is greatly needed for the effective management of fish stocks.

G. Hempel Early Life History of Marine Fish: the Egg Stage, xvi, 70 pp. University of Washington Press, 1979. (Washington Sea Grant Publication.) Paperback only. Price £4·50/$7·50.

G. Hempel Early Life History of Marine Fish: the Egg Stage, xvi, 70 pp. University of Washington Press, 1979. (Washington Sea Grant Publication.) Paperback only. Price £4·50/$7·50.

The "Critical Period" in the Early Life History of Marine Fishes

The "Critical Period" in the Early Life History of Marine Fishes