An investigation of the substrate preference of white sturgeon (Acipenser transmontanus) eleutheroembryos

Abstract

Fifty white sturgeon (Acipenser transmontanus) eleutheroembryos (average size 0.17 g) were placed onto each of four quadrants (0.45 m 2 quadrant )1 ; 200 fish tank )1 ) of different sized substrates in four circular tanks (approximately 562 L). Each of three quadrants had a different size substrate and the fourth quadrant was left bare. We used one replicate of smaller size substrates (0.5-11.9 mm) and one replicate of larger size substrates (21.7-88 mm). It was found that the white sturgeon eleutheroembryos preferred substrate with an average size (longest diameter) of 12 mm (11.9) in the smaller substrate range and 22 mm (21.7) in the larger substrate range. These data improve our knowledge of white sturgeon early life history, and if confirmed in the wild can be used to protect areas that are crucial for white sturgeon recruitment and survival.

The effect of substrate rearing on the growth, development, and survival of larval white sturgeon (Acipenser transmontanus) during early ontogeny.

“…Two substrate treatments were used: gravel (3 cm depth) and no substrate (bare conditions). The gravel substrate and the grain size used were based in part on the findings of a white sturgeon YSL substrate preference study by Bennett et al (2007) and from results of my previous work (Boucher and McAdam, unpublished). A mixture of gravel was used ranging from pea gravel to 2 cm gravel (11.9 -21.7 mm in longest axis).…”

“…While habitat requirements of larval sturgeon are unclear, there is increasing evidence that gravel substrate is important during early developmental stages. Bennett et al (2007) found that larval white sturgeon showed a preference for gravel substrates soon after hatching. Other studies have also shown that in both lab and riverine conditions, sturgeon larvae rear in gravel (Gessner et al 2009;McAdam 2011) and perform better in terms of growth and survival when provided with gravel substrate (Chapter 1).…”

“…YSL Atlantic sturgeon (A. oxyrinchus) and shortnose sturgeon (A. brevirostrum) seek cover shortly after hatch (Kynard and Horgan 2002); when A. brevirostrum YSL were prevented from seeking cover they displayed swim-up and drift behavior (Richmond and Kynard 1995). Bennett et al (2007) found that white sturgeon YSL showed a preference for gravel substrates, stating that it is likely that larvae developing on a substrate unsuitable for them may have lower condition factor (weight to length ratio) resulting in a reduced chance of survival in the wild. Gessner et al (2009) not only found that larvae continued to swim until adequate substrate was found, but they also showed higher survival when reared in gravel.…”

“…Substrates have often been used in salmonid hatcheries in the culture of alevins, as this generally produces larger fry than rearing methods without substrate (Bams 1969;Fuss and Johnson 1982;Murray and Beacham 1986;Peterson and Martin-Robichaud 1995). While a growing body of literature indicates that benthic substrates may play a significant role in the early life history of sturgeon, only a few studies have been done to quantify the potential effect of gravel rearing on sturgeon recruitment (Gadomski and Parsley 2005;McAdam et al 2005;Bennett et al 2007;Gessner et al 2009;McAdam 2011).…”

“…If so, then the gravel substrate preference of white sturgeon YSL identified by Bennett et al (2007) may indicate that gravel rearing offers a way to maximize metabolic scope. This line of reasoning is further supported by Claireaux and Lefranfois (2007) who suggest that an environment that provides increased growth may indicate increased metabolic scope.…”