Record Details
Utilization of dietary protein by the mussel, Mytilus edulis trossulus (Linnaeus 1758)
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Utilization of dietary protein by the mussel, Mytilus edulis trossulus (Linnaeus 1758) |
| Names |
Kreeger, Daniel A.
(creator) Langdon, Christopher J. (advisor) |
| Date Issued | 1992-08-04 (iso8601) |
| Note | Graduation date: 1993 |
| Abstract | Protein microcapsules (PM) were developed as a tool for investigating aspects of dietary protein utilization by mussels, Mytilus edulis trossulus. Digestion of PM in vitro by protease, trypsin, amylase and extracts from the gut of mussels varied significantly depending on the type of protein encapsulated or whether carbohydrates were added to the capsule matrix. In contrast, digestion and assimilation efficiencies of PM by mussels in vivo, as determined with radiotracer techniques, did not differ among PM that varied in biochemical composition. Therefore, in vivo digestion of PM by the mussel's digestive system is poorly predicted by in vitro enzyme assays. The effect of dietary protein content on the growth rate of juvenile M. edulis trossulus was investigated. Dissolved concentrations of inorganic nitrogen added to cultures of microalgae (Isochrysis galbana clone T-Iso) were manipulated to produce algae that either contained 28% or 43% protein (of total dry weight). Mussels fed high-protein (HP) algae grew nearly twice as fast as mussels fed an isocaloric ration of low-protein (LP) algae. When PM were added to the LP algal diet, however, mussels grew at rates equal to those of mussels fed HP algae alone; whereas, growth rates of mussels given an extra ration of LP algae were not similarly improved. Therefore, growth of juvenile M. edulis trossulus can be limited by dietary protein content regardless of dietary energy content. Seasonal variation in the utilization of dietary protein by adult mussels was examined by measuring assimilation rates of ¹⁴C-labeled PM and digestive proteolytic activities of mussels collected from Yaquina Bay. Protein assimilation rates and gut proteolytic activities were greatest during late winter and spring, just prior to the mussel's peak reproductive condition in May. In addition, assimilated protein was metabolically conserved from catabolism during May. As a result of high springtime protein assimilation rates and metabolic conservation of assimilated protein, protein accumulated in mussel tissues during March to May. The seasonal pattern in the utilization of dietary protein by adult Mytilus edulis trossulus may have been governed by seasonal changes in mussel physiology (eg. protein requirements) associated with reproduction. |
| Genre | Thesis/Dissertation |
| Topic | Mussels |
| Identifier | http://hdl.handle.net/1957/33136 |
