Chlorophyte and rhodophyte starches as factors in diet choice by marine herbivorous fish

Zemke‐White, W. Lindsey; Clements, Kendall D.

doi:10.1016/s0022-0981(99)00056-8

Cited by 51 publications

(30 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Seeto et al (42) demonstrated that the gut flora in the Australian herbivorous fish species Odax cyanomelas had a high capacity for the utilization of mannitol, and given the above concluded that mannitol was an important substrate for fermentation. Algal cell wall polysaccharides such as alginic acid and carrageenan are likely to be resistant to endogenous fish enzymes, and even algal storage compounds such as starch and floridean starch can be highly resistant to fish amylase (51). Thus, there is potentially a huge range of algal substrates which could be fermented to acetate in the gut of these fishes.…”

Section: Discussionmentioning

confidence: 99%

Hindgut Fermentation in Three Species of Marine Herbivorous Fish

Mountfort

Campbell

Clements

2002

Appl Environ Microbiol

157

156

View full text Add to dashboard Cite

Symbioses with gut microorganisms provides a means by which terrestrial herbivores are able to obtain energy. These microorganisms ferment cell wall materials of plants to short-chain fatty acids (SCFA), which are then absorbed and used by the host animal. Many marine herbivorous fishes contain SCFA (predominantly acetate) in their hindgut, indicative of gut microbial activity, but rates of SCFA production have not been measured. Such information is an important prerequisite to understanding the contribution that gut microorganisms make in satisfying the energy needs of the fish. We have estimated the rates of acetate production in the gut of three species of temperate marine herbivorous fish from northeastern New Zealand: Kyphosus sydneyanus (family Kyphosidae), Odax pullus (family Odacidae), and Aplodactylus arctidens (family Aplodactylidae). Ex vivo preparations of freshly caught fish were maintained with their respiratory and circulatory systems intact, radiolabeled acetate was injected into ligated hindgut sections, and gut fluid was sampled at 20-min intervals for 2 h. Ranges for acetate turnover in the hindguts of the studied species were determined from the slope of plots as the log of the specific radioactivity of acetate versus time and pool size, expressed on a nanomole per milliliter per minute basis. Values were 450 to 570 (K. sydneyanus), 373 to 551 (O. pullus), and 130 to 312 (A. arctidens). These rates are comparable to those found in the guts of herbivorous reptiles and mammals. To determine the contribution of metabolic pathways to the fate of acetate, rates of sulfate reduction and methanogenesis were measured in the fore-, mid-, and hindgut sections of the three fish species. Both rates increased from the distal to proximal end of the hindgut, where sulfate reduction accounted for only a small proportion (<5%) of acetate methyl group transformed to CO 2 , and exceeded methanogenesis from acetate by >50-fold. When gut size was taken into account, acetate uptake from the hindgut of the fish species, determined on a millimole per day per kilogram of body weight basis, was 70 (K. sydneyanus), 18 (O. pullus), and 10 (A. arctidens).Marine herbivorous fish harbor a great diversity of gut microorganisms (1, 9-11, 15, 23, 33, 40, 43, 45). Despite their importance in terms of microbial biodiversity, the role of these microorganisms in the digestive processes of the host fish is not well understood. In contrast, it is well known that most terrestrial vertebrate herbivores contain populations of symbiotic organisms that play a key role in digestion by breaking down plant cell walls (cellulose and hemicellulose) to simple compounds such as short-chain fatty acids (SCFA). The SCFA are then taken up by the host and are used for energy generation and biosynthesis (44).The algae eaten by marine herbivorous fishes are phylogenetically diverse. Unlike terrestrial plants, algae are supported by water and have a lower proportion of structural elements to cell contents (8). Consequently, it is not surprising that ...

show abstract

Section: Discussionmentioning

confidence: 99%

Hindgut Fermentation in Three Species of Marine Herbivorous Fish

Mountfort

Campbell

Clements

2002

Appl Environ Microbiol

157

156

View full text Add to dashboard Cite

show abstract

“…The quantification of carbohydrase activity was performed using a technique modified from Zemke-White & Clements (1999). Anterior intestinal tissue was homogenized in 50 m Tris-maleate buffer (pH 7·3) containing 10 m CaCl 2 , and incubated with an appropriate substrate.…”

Section: Endogenous Carbohydrase Activitymentioning

confidence: 99%

Diet and endogenous carbohydrases in the temperate marine herbivorous fish Kyphosus sydneyanus

Moran

Clements

2002

Journal of Fish Biology

View full text Add to dashboard Cite

Stomach content analysis showed that Kyphosus sydneyanus collected by spearing from coastal reefs near Leigh, north-east New Zealand, is herbivorous throughout its post-settlement life. All size classes collected consumed a wide range of macroalgae, predominantly the phaeophytes Carpophyllum maschalocarpum and Ecklonia radiata, and the rhodophytes Gigartina macrocarpa and Caulacanthus ustulatus. Multivariate analysis of variance and discriminant function analysis showed an ontogenetic diet shift, with gut contents dominated by rhodophytes and chlorophytes in juveniles and by phaeophytes in adults. No significant seasonal variation in diet was apparent for any size class. Amylase and amylopectinase activity was highest in the smaller size classes. Laminarinase activity was relatively low throughout all size classes, and did not correlate with the ontogenetic increase in phaeophyte consumption. The activity of endogenous enzymes hydrolysing starch broadly correlated with rhodophyte consumption in adult specimens of three other species of marine herbivorous fishes: Odax pullus, Girella tricuspidata and Parma alboscapularis; laminarin hydrolysis, however, was negatively correlated with phaeophyte consumption. Overall, the diet and enzyme results suggest that juvenile K. sydneyanus rely mainly on the endogenous digestion of rhodophytes and chlorophytes, while exogenous (microbial) digestion is used to digest the phaeophyte-dominated diet of adults.

show abstract

“…were the most consumed algae and were selected by at least four fish species among the most important. In general, red and green algae tend to be favored in the diets of most herbivorous fishes due to their higher nutritional value when compared to brown algae (Zemke-White and Clements, 1999;Patarra et al, 2011), although the nutritional composition of algae is highly Table 1 Fish species (with their related family and trophic classification) that feed on macroalgae offered on the assays with their respective relative mass standardized bite and relative biomass. variable and some brown algae have been shown to present high protein contents (Montgomery and Gerking, 1980;Kaehler and Kennish, 1996;McDermid and Stuercke, 2003).…”

Section: Discussionmentioning

confidence: 99%