Optimal feeding strategy of the temperate herbivorous fish Aplodactylus punctatus: the effects of food availability on digestive and reproductive patterns

Oecologia ◽  
1994 ◽  
Vol 99 (1-2) ◽  
pp. 118-123 ◽  
Author(s):  
Cristian W. Caceres ◽  
Leopoldo S. Fuentes ◽  
F. Patricio Ojeda
Keyword(s):  
Food Availability ◽  
Feeding Strategy ◽  
Herbivorous Fish ◽  
Reproductive Patterns

Seasonal changes in the diet, food availability and food preference of the greater bilby (Macrotis lagotis) in south-western Queensland

2001 ◽  
Vol 28 (2) ◽  
pp. 121 ◽  
Author(s):  
Lesley A. Gibson
Keyword(s):  
Food Availability ◽  
Seasonal Changes ◽  
Arid Zone ◽  
Feeding Strategy ◽  
Frequency Of Occurrence ◽  
Plant Component ◽  
Faecal Pellets ◽  
Food Items ◽  
Invertebrate Prey ◽  
Prey Items

Diet and food availability of the greater bilby (Macrotis lagotis), was examined at two sites and over two summer and two winter seasons in Astrebla Downs National Park in south-western Queensland. The presence of both invertebrate and plant material in almost all faecal pellets (99.6% and 98.5%, respectively) indicated that bilbies in south-western Queensland are omnivorous. The plant component of the bilby diet consisted predominantly of Dactyloctenium radulans seeds (frequency of occurrence: 94.4%). The major invertebrate prey items were Isop-tera (termites, 73.1%) and Formicidae (ants, 77.6%). The frequency of occurrence of invertebrates in faecal pellets was higher during summer than winter, but the frequency of occurrence of plants was relatively constant regardless of season. Within the invertebrate categories, Isoptera and Acrididae (grasshoppers) displayed the greatest seasonal difference, with a significantly higher proportion of both categories in the diet during summer than winter at both study sites. The availability of invertebrate prey items also varied with season, and for most taxa, frequency of oc-currence was significantly higher in summer than winter. In contrast, the frequency of occurrence of seeds and bulbs (Cyperus bulbosus) varied only slightly with season. Seasonal changes in food availability were reflected by variation in dietary composition; however, relative proportions of some dietary items differed from their proportional availability. Therefore, bilbies were considered to be qualitatively opportunistic; selecting more invertebrates when their apparent availability increased, but continually exploiting the available seeds and bulbs. Additionally, although bilbies appeared to have some preferences for particular food items, several food items were selected almost randomly, and therefore bilbies were also considered to be dietary generalists. Such an opportunistic feeding strategy is advantageous to an arid-zone species as it permits the continuous exploitation of food resources that are unpredictable in their availability both spatially and temporally.

scholarly journals Association of seasonal reproductive patterns with changing food availability in an equatorial carnivore, the spotted hyaena (Crocuta crocuta)

Reproduction ◽  
1999 ◽  
Vol 116 (1) ◽  
pp. 87-93 ◽  
Author(s):  
K. E. Holekamp ◽  
M. Szykman ◽  
E. E. Boydston ◽  
L. Smale
Keyword(s):  
Food Availability ◽  
Crocuta Crocuta ◽  
Reproductive Patterns

scholarly journals Trophic niche of the invasive gregarious species Crepidula fornicata, in relation to ontogenic changes

2020 ◽  
Author(s):  
Thibault Androuin ◽  
Stanislas F Dubois ◽  
Cedric Hubas ◽  
Gwendoline Lefebvre ◽  
Fabienne Le Grand ◽  
...  
Keyword(s):  
Organic Matter ◽  
Food Availability ◽  
Phytoplankton Bloom ◽  
Feeding Strategy ◽  
Trophic Niche ◽  
Late Winter ◽  
Differential Growth ◽  
Spring Phytoplankton Bloom ◽  
Crepidula Fornicata ◽  
Trophic Markers

Crepidula fornicata is a common and widespread invasive gregarious species along the European coast. Among its life-history traits, well documented ontogenic changes in behavior (i.e., motile male to sessile female) suggest a potential shift in feeding strategy across its life stages. Considering the ecological significance of this species in colonized areas, understanding how conspecifics share the trophic resource is crucial. Using fatty acids (FA) and stable isotopes (SI) as complementary trophic markers, we conducted a field survey between late winter and spring to investigate the trophic niche of three ontogenic stages of C. fornicata that bear different sexual (male/female) and motility (motile/sessile) traits. Potential trophic sources were characterized by their pigment, FA and SI compositions and showed well discriminated compositions over the studied period. We showed that the biofilm covering C. fornicata shells harbored a higher biomass of primary producers (i.e., chlorophytes and diatoms) than the surrounding sediment. Over the studied period, we observed a covariation between the three ontogenic stages for both FA and SI compositions which suggest that the trophic niche of C. fornicata does not change significantly across its benthic life. During periods of low food availability, slipper limpets displayed an opportunistic suspension-feeding behaviour, relying on both fresh and detrital organic matter, likely coming from superficial sedimentary organic matter. However, during high food availability (i.e., spring phytoplankton bloom), all ontogenic stages largely benefited from this fresh supply of organic matter (pelagic diatoms in this case). The three ontogenic stages showed consistent differences in FA composition, and to a lesser extent in SI composition. These differences persist over time, as they originate from ontogenic physiological changes (differential growth rates, metabolic rate or gametogenesis) rather than diet discrepancies. This study revealed that multiple trophic markers allow high complementary to characterize organic matter as well as food partitioning between conspecific organisms.

SIZE-DIVERSITY TRENDS AND FEEDING-STRATEGY DISTRIBUTIONS IN BRACKISH-WATER ICHNOFOSSILS

2016 ◽  
Author(s):  
Murray Gingras ◽  
◽  
Eric R. Timmer ◽  
Eric Ditzler ◽  
John-Paul Zonneveld ◽  
...  
Keyword(s):  
Brackish Water ◽  
Feeding Strategy ◽  
Size Diversity

Reproduction

2017 ◽  
Author(s):  
Derek Burton ◽  
Margaret Burton
Keyword(s):  
Reproductive Behaviour ◽  
Life Cycles ◽  
Freshwater Species ◽  
Adult Fish ◽  
Reproductive Patterns ◽  
Cell Divisions ◽  
Early Stages ◽  
External Cues ◽  
Neural Factors

Interspecific fish reproductive patterns, outputs and life cycles display the greatest variability within the vertebrates. Early stages of oogenesis can be repeated in adult fish, contrasting with mammals; the pre-set sequence of cell divisions in gametogenesis is otherwise similar and is described in detail. Most fish deposit much yolk (vitellogenesis) in developing eggs. Migrations, beach-spawning and mouth-brooding are some of the interesting variations. Fertilization is predominantly external but is internal in some groups such as chondrichthyans. The omission of annual reproduction is well established in some freshwater species and the idea that this may also be the case for marine teleosts is gaining acceptance. This should be taken into account for intensively fished species. The possible roles of external cues, hormones, pheromones and neural factors acting as ‘switches’ and coordinators in gametogenesis and reproductive behaviour are discussed.

scholarly journals Effect of peripartal feeding strategy on colostrum yield and composition in sows1

2014 ◽  
Vol 92 (8) ◽  
pp. 3557-3567 ◽  
Author(s):  
R. Decaluwé ◽  
D. Maes ◽  
A. Cools ◽  
B. Wuyts ◽  
S. De Smet ◽  
...  
Keyword(s):  
Feeding Strategy
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