Thiamine and Thiaminase Status in Forage Fish of Salmonines from Lake Michigan

Abstract

Dietary sources of thiamine (vitamin B 1 ) and thiamine-degrading enzymes (thiaminases) are thought to be primary factors in the development of thiamine deficiency among Great Lakes salmonines. We surveyed major forage fish species in Lake Michigan for their content of thiamine, thiamine vitamers, and thiaminase activity. Concentrations of total thiamine were similar (P Յ 0.05) among most forage fishes (alewife Alosa pseudoharengus, bloater Coregonus hoyi, spottail shiner Notropis hudsonius, deepwater sculpin Myoxocephalus thompsonii, yellow perch Perca flavescens, ninespine stickleback Pungitius pungitius, and round goby Neogobius melanostomus) and slightly lower in rainbow smelt Osmerus mordax. Concentrations of total thiamine were all above the dietary requirements of coldwater fishes, suggesting the thiamine content of forage fish is not the critical factor in the development of thiamine deficiency in Lake Michigan salmonines. Thiamine pyrophosphate was the predominant form of thiamine in most species of forage fish, followed by free thiamine and thiamine monophosphate. Total thiamine was slightly greater in summer collections of alewife and rainbow smelt than in spring and fall collections, but the same was not true for bloater. Thiaminase activity varied among species and was greatest in gizzard shad Dorosoma cepedianum, spottail shiner, alewife, and rainbow smelt. Thiaminase activity in alewife varied among collection locations, season (greatest in spring), and size of the fish. Size and condition factors were positively correlated with both total thiamine and thiaminase activity in alewife. Thus, thiamine and thiaminase activity in forage fishes collected in Lake Michigan varied among species, seasons, year caught, and size (or condition). Therefore, multiple factors must be considered in the development of predictive models for the onset of thiamine deficiency in Great Lakes salmonines. Most importantly, thiaminase activity was great in alewives and rainbow smelt, suggesting that these prey fish are key causative factors of the thiamine deficiency in Great Lakes salmonines.

Pathology, Physiologic Parameters, Tissue Contaminants, and Tissue Thiamine in Morbid and Healthy Central Florida Adult American Alligators (Alligator Mississippiensis)

“…. Furthermore, Honeyfield et al (2005) experimentally reproduced early mortality syndrome in lake trout fry and observed adult mortality (as previously reported by Brown et al [2005b]). Signs and symptoms of EMS were observed when fish were fed diets containing thiaminase (Honeyfield et al, 2005).…”

“…Furthermore, Honeyfield et al (2005) experimentally reproduced early mortality syndrome in lake trout fry and observed adult mortality (as previously reported by Brown et al [2005b]). Signs and symptoms of EMS were observed when fish were fed diets containing thiaminase (Honeyfield et al, 2005). Salt water crocodiles with signs and symptoms similar to Florida alligators have been reported to be thiamine responsive, although the cause of the deficiency was not thiaminase related (Jubb, 1992).…”

“…Adult alligator mortality has remained low since then. Gizzard shad are a rich source of thiaminase (Tillitt et al, 2005) and are reported to be an important dietary component for alligators (Rice, 2004;Rice et al, 2007). Lake Griffin gizzard shad (avg.…”

“…Studies showed that fry mortality from yolk sac edema was linked to halogenated hydrocarbon exposure (Spitsbergen et al, 1991;Walker and Peterson, 1991). After careful review of the report by Mac et al (1985), the signs and symptoms of dioxin toxicity were not consistent with that of EMS (Horning et al, 1998;Marcquenski and Brown, 1997); thiamine deficiency was definitively shown to be the cause of salmonid fry mortality (Honeyfield et al, 2005). In the case of Lake Griffin, there are no data on the thiamine status of adult alligators that were dying, but observations from affected alligators (Schoeb et al, 2002) were consistent with reports related to thiamine deficiency in salmonids; these included specific neurologic lesions in Atlantic salmon (Lundströ m et al, 1999), impaired motor coordination (abnormal swimming behavior; Marcquenski and Brown, 1997), and adult mortality .…”

“…Gizzard shad (Dorosoma cepedianum), like alewife and herring, contain thiaminase, an enzyme that degrades thiamine (Tillitt et al, 2005). Gizzard shad are an abundant fish in many Florida lakes and are eaten by alligators (Delany and Abercrombie, 1986;Delany et al, 1999;Rice, 2004).…”