Food composition and feeding habits of Astatotilapia flaviijosephi (Lortet) in Lake Kinneret (Israel)

1985 ◽  
Vol 26 (5) ◽  
pp. 503-507 ◽  
Author(s):  
P. Spataru ◽  
M. Gophen
1996 ◽  
Vol 47 (6) ◽  
pp. 801 ◽  
Author(s):  
EE Di Giacomo ◽  
MR Perier

Morphology of the main digestive features of cockfish, Callorhinchus callorhynchus, is described and linked to feeding habits. Composition of the diet and size-selective foraging of this species on scallops was studied in northern Patagonian waters and analysed in relation to depth, sex and size. Three species of bivalve molluscs (Pitar rostratus, Aequipecten tehuelchus and Ennucula puelcha) and flabelligerid polychaetes were predominant in the diet of males. The scallop Zygochlamys patagonica dominated the diet of females. The diet of juveniles consisted of small gastropods (Olivella sp.), bivalves with fragile shells (e.g. Pandora cistula), amphipods and polychaetes. Differences in food composition between sexes and between juveniles and adults are attributed to two factors: extrinsic (concerning prey availability) and intrinsic (concerning the morphology and behaviour of the predator). Size-selective foraging on two species of scallops, Aequipecten tehuelchus (subject to commercial fishing) and Zygochlamys patagonica, was found in adults; it is argued that maximum scallop prey size is constrained by the strength of the crushing apparatus of the cockfish. The diet of the cockfish is compared with that of other holocephalans. It is concluded that species of Callorhinchus can be generally characterized as benthic foragers that specialize in crushing shelled invertebrate prey.


Author(s):  
Andreza Da Silva Nascimento ◽  
Jonas De Assis Almeida Ramos

<p>The knowledge of natural fish feeding is important to understand the species feeding habits and how they interact with the environment. In addition to that, this kind of research can provide relevant data to improve the capture of these animals, considering their economy and social importance. This study aimed to analyze the food composition of Larimus breviceps specimens from the northern coast of Cabedelo city, evaluating the importance of each food item for their diet. The specimens came from the local artisanal fisheries. In laboratory, the individuals were identified, measured and dissected to remove the stomachs content and then examined. Three different analyzes were performed, percentage by frequency of occurrence, by number and by weight, then the index of relative importance (IRI%) was computed. In total, 30 stomachs were analyzed, 15 distinct food items were identified, the most representative prey were fish fragments, Copepoda, Gammaridae, Decapoda (shrimp), algal fragments and synthetic material. Given the results, the diet of this species becomes more diversified as young individuals reach the adults size, and ingest marine debris which indicates an anthropogenic impact.</p>


Author(s):  
Alexandra Silva

The feeding habits of John Dory (Zeus faber) were studied, based on the analysis of stomach contents from fish sampled in five groundfish surveys. These surveys were carried out off the Portuguese coast during different seasons between 1990 and 1992. The main aspects of feeding biology analysed in this paper are: ontogenetic diet changes, temporal variations in food composition and feeding intensity. Multivariate methods were used to investigate ontogenetic diet shifts. Two main length groups were identified: 8.0–24.9 cm fish, feeding mainly on dragonets and silvery pout, and 25.0–55.9 cm fish whose diet was mainly composed of blue whiting and snipefish. A transitional phase (24.0–30.9 cm fish) with a mixed food composition was observed. This ontogenetic diet shift does not seem to correspond to any important change in body morphology but it does coincide with the onset of sexual maturity in the species.John Dory switched from a diet of small prey species with more pronounced benthic behaviour to a diet of larger schooling pelagic species. This suggests parallel evolution to more pelagic foraging behaviour. However, John Dory feeding habits appear to be largely controlled by the availability and accessibility of prey species: (i) the diet of adult John Dory is dominated by very abundant species; (ii) shifts in the main prey items between different times of the year and between different areas seem to be related both with their absolute and relative abundance in the environment and with the overlap between the depth distribution of predator and prey.


Hydrobiologia ◽  
1987 ◽  
Vol 144 (1) ◽  
pp. 77-82 ◽  
Author(s):  
P. Spataru ◽  
W. J. A. R. Viveen ◽  
M. Gophen

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