Title

Ontogenetic diet shift in the June sucker Chasmistes liorus (Cypriniformes, Catostomidae) in the early juvenile stage

Keywords

zooplankton, Copepoda, Brachionus, size-structured interactions, foraging, development

Abstract

Ontogenetic diet shifts are common in fishes and often occur during early life stages. The larval and early juvenile period is critical in the life cycle of the endangered June sucker, Chasmistes liorus (Teleostei: Catostomidae). High larval and juvenile mortality leads to low recruitment to the breeding population and hence a declining natural population. To understand diet composition and dynamics in June sucker at early life stages, diet was quantified and compared to available food items in the natural environment during the early juvenile stage. Rotifers (Brachionus sp.) were the primary diet item at week 10, but by week 12 a small cyclopoid copepod (Microcyclops rubellus) became predominant. Availability of diet items varied little across the experimental period. The increase in size of young suckers may explain this rapid dietary shift, but there are some inconsistencies with the size selection argument. This diet shift represents an important nutritional change that should be considered in development of diets for young June sucker and in assessing suitability of nursery habitats.

Original Publication Citation

Kreitzer, J. D., Belk, M. C., Gonzalez, D. B., Tuckfield, R.C., Shiozawa, D.K., and Rasmussen, J. E. 2010. Ontogenetic diet shift in the June sucker Chasmistes liorus (Cypriniformes, Catostomidae) in the early juvenile stage. Ecology of Freshwater Fish 19:433-438.

Document Type

Peer-Reviewed Article

Publication Date

2010-08-15

Publisher

Ecology of Freshwater Fish

Language

English

College

Life Sciences

Department

Biology

University Standing at Time of Publication

Full Professor

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