meaningful ecological, physiological and behavioral research developed once 
larvae could be routinely cultured. A myriad of foods has been used to rear 
marine fish larvae (64), but five foods have been more successful in recent 
years for meeting larval nutritional requirements. These are the rotifer 
Brachionus plicatilis, the nauplius of brine shrimp Artemia salina , copepods 
from wild plankton collections, the harpacticoid copepods Tisbe and Tigriopus 
spp., and the naked di no flagellate Gymnodinium splendens. 
Prey Concentrations 
Marine fish larvae are visual feeders, with limited ability to search a volume 
of water for suitable food items during a unit of time. Suitable items usually 
are living organisms of a size that can be ingested, are nutritionally adequate, 
and are present at concentrations which allow a larva to encounter enough 
items during a day to meet its metabolic demands and to provide some excess 
for growth. Typical marine fish larvae are 2-3.5 mm long when they begin to 
search actively for food. Acceptable prey usually are 20-150 jum in breadth (7, 
31, 56, 92). Some large and rather atypical larvae, like Atlantic herring, Clupea 
harengus , or plaice Pleuronectes platessa, can begin feeding on items in excess 
of 300 jum in breadth (10, 80, 82). Perhaps not surprisingly, required 
concentrations of prey for newly-feeding larvae have been shown to vary 
greatly in laboratory studies, the variation in large part reflecting size 
differences in the prey that has been offered. 
Prey concentrations that have been used successfully to rear larvae have 
ranged from 1 x 10^ to 2 x 10^ per liter, although required concentrations for 
significant survival probably lie in the range 10^ to 10^ per liter. The highest 
reported concentrations (1-2 x 10^ per liter) were of the large dinoflagellate 
Gymnodinium splendens , which can be used to culture northern anchovy 
larvae during the first week of life (47, 57, 95). Lowest concentrations (442 
per liter) were of brine shrimp Artemia salina nauplii used to culture Atlantic 
herring larvae (82, 83). Neither G. splendens nor A. salina is usually available to 
marine fish larvae in nature, although Kiefer and Lasker (53) recently have 
shown that G. splendens may be present at 14 x 1(L per liter in the 
chlorophyll maximum layer of the Southern California Bight. Northern 
anchovy larvae can concentrate in the chlorophyll maximum layer and can feed 
on G. splendens when its concentration exceeds 2x10^ per liter (56). The 
most common prey reported from stomach analyses of marine fish larvae in 
nature are nauplii and other stages of copepods. Using copepod nauplii as food 
Houde (45) reported 10 percent survival at metamorphosis when per liter 
nauplii concentrations were 34 for sea bream Archosargus rhomboidalis, 107 
for bay anchovy Anchoa mitchilli, and 130 for lined sole, Achirus lineatus. 
Other studies with wild plankton (predominantly copepod nauplii) as prey 
have reported higher concentrations required for significant survival than those 
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