Hatchery Performance Attributes of Juvenile Lake Sturgeon Fed Two Natural Food Types

Abstract

The use of stocking programs to rehabilitate depressed populations of lake sturgeon Acipenser fulvescens requires the optimization of early life stage growth in hatchery settings. We evaluated the performance of juvenile lake sturgeon fed different proportions of two natural food types—adult brine shrimp Artemia spp. and larval bloodworms Chironomus spp.—over a 10‐week laboratory experiment. The following five diet treatments were provided: (1) 100% bloodworms; (2) 75% bloodworms : 25% brine shrimp; (3) 50% bloodworms : 50% brine shrimp; (4) 25% bloodworms : 75% brine shrimp; and (5) 100% brine shrimp. Lake sturgeon growth was positively related to bloodworm content in the diet and was significantly different among treatments. Although the initial sizes of fish were similar, mean fork length and wet weight were greatest for the 100% bloodworm treatment (183.1 mm and 37.5 g, respectively) and lowest for the 100% brine shrimp diet (118.4 mm and 9.5 g) by the end of the study. Mean specific and absolute growth rates in length (0.93% and 1.28 mm/d, respectively) and weight (2.61% and 0.45 g/d) were greatest for the 100% bloodworm diet, followed by the other treatments in order of decreasing amount of bloodworms in the diet. Percent weight gain (525%) and food conversion efficiency (67%) were also greatest for the 100% bloodworm diet, followed by the other treatments in order of decreasing dietary bloodworm content. Whole‐body protein (13.9%), lipid (2.5%), and gross‐energy (3.77 kJ/g) content were greatest for fish fed 100% bloodworms, with these proximate‐composition measures also ranked in order of decreasing dietary bloodworm content for the other treatments. We recommend that juvenile lake sturgeon reared in hatchery environments be fed high proportions of bloodworms to maximize growth, body size, and lipid content for rehabilitation stocking programs.

Review of a species in peril: what we do not know about lake sturgeon may kill them

“…For example, Stelzer et al (2008) analyzed the gut content of lake sturgeon in Lake Winnebago and found that gizzard shad (Dorosoma cepedianum) and Chironomus plumosus larvae comprise 56% and 33% of gut content mass, respectively, which was confirmed with a mixing model using ␦ 13 C and ␦ 15 N. Additionally, a study by Anderson et al (2012) and Choudhury et al (1996) confirmed the importance of Chironomidae in the Lake Winnebago diet and found that the chironomids were in high enough abundance to support the sturgeon. A diet study conducted by Volkman et al (2004) on juvenile lake sturgeon in hatcheries found that blood worms (Chironomus spp.) maximize growth, adding evidence to their importance in the wild.…”

Production and Enrichment of Chironomid Larva with Different Levels of Vitamin C and Effects on Performance of Persian Sturgeon Larvae

“…Larval growth and ascorbic acid analysis.-Growth performance included weight gain (WG), daily absolute growth rate for length (AGR L ) and weight (AGR W ), specific growth rate in length (SGR L ) and weight (SGR W ), body weight increase (BWI) and feed conversion efficiency (FCE), which were evaluated according to the following production criteria (Volkman et al 2004;Falahatkar et al 2006):…”

“…The main problems of using live feed for fish larval rearing are availability and price (Cahu and Zambonino 2001), and many fish farmers can benefit from calculating feed efficiency. Volkman et al (2004) compared nonenriched frozen chironomids with Artemia spp. in feeding juvenile Lake Sturgeon Acipenser fulvescens; they found significantly higher FCE, WG, AGR W and SGR W in fish fed chironomids, which partially supports our results.…”

“…These insects have a phenomenal capacity that allows them to produce approximately 2,000 eggs per reproduction cycle (Armitage 1995). Nutritional quality of chironomids includes high protein levels (approximately 55.7% in dry weight) and presence of most essential amino acids (Bogut et al 2007), making them suitable live feed for most fishes, including sturgeons (Volkman et al 2004). Nevertheless, live feed do not always contain all the required ingredients for fish larvae, and to compensate these insufficiencies, they need to be enriched with some inherent micronutrients to be comparable with other feeds to provide the requirements for growth and survival (Dabrowski 2001).…”

Fine tuning of feeding practices for hatchery produced Persian sturgeon,Acipenser persicusand Beluga sturgeon,Huso huso

“…This has prompted a great deal of interest in the develop-ment of an artificial larval microdiet (MD) as an economic alternative to live food. The successful use of Artemia nauplii alone or co-fed with a commercial diet at the start feeding or during early development of different sturgeon species has been reported by a number of researchers (Bardi et al 1998;Dilauro, Krise & Fynn-Aikins 1998;Mohler, Kim King & Farrell 2000;Volkman, Pangle, Rajchel & Sutton 2004). This may be due to the composition, palatability or physical characteristics of the dry feed (Person Le Ruyet, Alexandre, Thebaud & Mugnier 1993), to the larva's inability to properly digest the feed (Holt 1993;Kolkovski, Tandler, Kissil & Gertler 1993;Walford & Lam 1993;Zambonino Infante & Cahu 1994), or to the low attractiveness of the non-mobile particle for the fish larva.…”