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Rainbow Darter ( Etheostoma caeruleum , Storer, 1845) predation on early ontogenetic stages of Lake Sturgeon ( Acipenser fulvescens , Rafinesque, 1817)
- Source :
- Journal of Applied Ichthyology. 36:151-158
- Publication Year :
- 2020
- Publisher :
- Hindawi Limited, 2020.
-
Abstract
- Previous molecular diet analysis identified lake sturgeon (Acipenser fulvescens, Rafinesque, 1817) DNA in the gastrointestinal tracts of stream‐resident rainbow darters (Etheostoma caeruleum, Storer, 1845) during the egg incubation, free embryo, and larval drift stages. The objectives of this experimental study were to: (a) quantify levels of predation by rainbow darters on lake sturgeon at the egg and free‐embryo stages; and (b) evaluate whether predation varied as a function of substrate size and rainbow darter body size. We conducted experimental trials in 23‐L polycarbonate tanks 0.41 m (L) × 0.33 m (W) × 0.30 m (D) with a standardized benthic area of 0.14 m². The tanks were randomly assigned one of two different substrate size classes: large rock (51.35 mm ± 0.91 mm) or small rock (27.68 mm ± 0.57 mm). We stocked individual rainbow darter, which were deprived of feed for 48 hr, with lake sturgeon (133 individuals/m²) in each of 12 replicates per ontogenetic stage and substrate type. The number of surviving lake sturgeon was quantified following a 24‐hr predation exposure period. We used a generalized linear model with a binomial distribution to assess the influence of ontogenetic stage, substrate size, and rainbow darter body size on proportional lake sturgeon survival. Predation on lake sturgeon occurred at both egg (6.25 ± 1.16 individuals, mean ± 2SE) and free embryo (3.08 ± 1.08 individuals, mean ± 2SE) stages. Egg proportional survival was generally lower than at the free embryo stage in both substrate sizes; however, free embryo proportional survival was greater in small substrate trials. Rainbow darter total length did not affect the probability of lake sturgeon survival at either developmental stage. Results demonstrate that rainbow darters prey on early ontogenetic stages of lake sturgeon, corroborating previous results based on genetic diet analysis. Results fill a major knowledge gap concerning the vulnerability of pre‐drift sturgeon to predation by an abundant river resident species that was previously discounted as a predator for early ontogenetic stages of lake sturgeon due to its small body size.
- Subjects :
- 0106 biological sciences
biology
010604 marine biology & hydrobiology
Zoology
04 agricultural and veterinary sciences
Aquatic Science
biology.organism_classification
01 natural sciences
Substrate (marine biology)
Predation
Etheostoma
Rainbow darter
Sturgeon
040102 fisheries
0401 agriculture, forestry, and fisheries
Acipenser
Lake sturgeon
Egg incubation
Subjects
Details
- ISSN :
- 14390426 and 01758659
- Volume :
- 36
- Database :
- OpenAIRE
- Journal :
- Journal of Applied Ichthyology
- Accession number :
- edsair.doi...........dd6e0a9e685001f07d24b4aa921075b4