Effects of Food and Feeding Factors on Laboratory-Reared Striped Bass Larvae

Abstract

Fluctuations in year-class size of striped bass (Morone saxatilis) are believed related to early-lifestage mortality. Factors associated with food and feeding of larvae were studied in the laboratory as they relate to mortality, point of no return, development, and energetics. Mortality of feeding larvae was directly related to density of Artemia salina nauplii. Highest mortality coincided with total oil globule absorption. Starved larvae lived an average 31 days after fertilization and did not display a well-defined point of no return. Growth and differentiation directly correlated with food density. Starvation affected the rate of ossification and altered cells and tissues as early as 7 days after hatching. Most of the endogenous energy of newly fertilized eggs is in oil. The rate of oil utilization was inversely related to food density. Daily food rations were estimated after ingestion and digestion rates were determined, and increased with larva size, age, and prey density.Between 1879 and 1882, 432 juvenile striped bass (Morone saxatilis) from the Navesink River, New Jersey, were released into the San Francisco Bay-Delta estuary. The transplant was so successful that, within 10 years, the commercial fishery landed 554 t (Skinner 1962). In less than 100 years, the Pacific range of striped bass has expanded south to 30 km below the United States-Mexico border and north to Barkley Sound, British Columbia (Miller and Lea 1972). Over the intervening years, sport and commercial catch records have indicated considerable fluctuations in the Pacific striped bass population (Smith and Kato 1979), and present estimates place the population at 33 to 40% of its peak 1960 estimate of 3.0 to 4.5 x 10 • fish. Recent field data indicate that mortality during the first 60 days after hatching determines the size of the adult population. Further, abundance of young-of-the-year juveniles is directly related to river outflows and diversion volumes in the Sacramento-San Joaquin River Delta (Chadwick et al. 1977). However, aside from direct export of eggs and larvae out of the estuary via water diversions, the actual causes of mortality remain undetermined. As part of a cooperative research program involving the

Age validation and growth of yolked larvae of <em>Patagonotothen tessellata</em> (Richardson, 1845) (Pisces: Nototheniidae) from the rocky littoral of the Beagle Channel, Argentina

“…Beyond this point, growth was interrupted and even negative growth could be registered. Similar situations were reported by Eldridge et al (1981) for Morone saxatilis Walbaum, 1792 and by Quantz (1985) for Scophthalmus maximus Linné, 1758. The multifold increase of body size that characterizes embryonic and larval growth (Kamler, 1992) is noticed in the fed larvae group.…”

Recruitment of striped bass in Chesapeake Bay: spatial and temporal environmental variability and availability of zooplankton prey

“…In 1996 and 2003, larvae were at their highest concentrations in the ETM region, where zooplankton prey exceeded 250 000 prey m -3 , levels far above the reported threshold prey levels for striped bass larvae that range from 50 000 to 100 000 prey m -3 (Eldridge et al 1981, Chesney 1989, Tsai 1991. In contrast, in poor recruitment years, such as 1999 and 2002, mean prey concentrations were approximately 2 orders of magnitude lower (average: < 2000 prey m -3 ) throughout the upper bay.…”

“…Minimum prey thresholds were defined as prey concentrations below which sharp declines in larval striped bass survival and growth occurred in 3 laboratory studies. One study tested Artemia nauplii as prey (Eldridge et al 1981), one tested Eurytemora affinis nauplii and other life stages (Tsai 1991), and one used a natural assemblage of zooplankton (Chick & Van Den Avyle 1999b). Local aggregations of zooplankton prey due to small-scale physical processes at spatial scales below the resolution of survey data analyzed here (1 to 10 km) may enhance feeding success (MacKenzie et al 1990).…”

“…Horizontal lines depict 3 different estimates (Eldridge et al 1981, Tsai 1991, Chick & Van Den Avyle 1999b) of minimum required prey levels for favorable survival and growth of striped bass Morone saxatilis larvae. ETM mid-point is indicated by a triangle on the x-axis (Fig.…”

Habitats essentiels des larves et des juvéniles de la nouvelle population de bar rayé du Saint-Laurent /

“…Rapid résorption of vitelline reserves (Eldridge et al 1981), short incubation time, and precocious exogenous feeding (Eldridge et al 1982, Tsai 1991, Wallus & Simon 2006 by striped bass larvae probably reduce the impact of maternal history on otolith chemistry, although this phenomenon is more common in salmonids. Consequently, the important maternal contribution in the otolith fingerprints of salmonids (Kalish 1990, Zimmerman & Reeves 2002 can be attributed to higher vitelline reserves (Peterson et al 1996) and the longer time taken to utilize them.…”