Observations on the Diet of Red Morwong, Cheilodactylus fuscus Castelnau (Pisces : Cheilodactylidae)

1979 ◽  
Vol 30 (1) ◽  
pp. 129 ◽  
Author(s):  
JD Bell
Keyword(s):  
Standard Length ◽  
Stomach Contents ◽  
Rocky Reef ◽  
Major Food ◽  
Seasonal Basis

Stomach contents of 104 C. fuscus (of 275-415 mm standard length) from rocky reef habitats in the Sydney region were analysed. This species was found to be entirely carnivorous, polychaetes, brachyurans, amphipods, gastropods and bivalves comprising the major food types and dominating the diet throughout the year. However, the relative proportions of these food types in the diet were found to vary considerably on a seasonal basis.

Feeding Flexibility in Northern Pike (Esox lucius): Fish versus Invertebrate Prey

1989 ◽  
Vol 46 (4) ◽  
pp. 666-669 ◽  
Author(s):  
Lauren J. Chapman ◽  
William C. Mackay ◽  
Craig W. Wilkinson
Keyword(s):  
Northwest Territories ◽  
Standard Length ◽  
Stomach Contents ◽  
Northern Pike ◽  
Esox Lucius ◽  
Frequency Of Occurrence ◽  
Pike Esox Lucius ◽  
Invertebrate Prey ◽  
Seasonal Basis

We describe the frequency of occurrence of fish and invertebrates in the stomach contents of northern pike (Esox lucius) from eight populations in Alberta and the Northwest Territories. Lakes were sampled one to eight times between 1979 and 1985, and a total of 899 pike were examined (mean standard length = 44 ± 8 cm, SD). Although northern pike are widely considered to be top aquatic piscivores, we found that the frequency of occurrence of invertebrates was high, at least on a seasonal basis, in some systems. In all of the lakes considered, the frequency of occurrence of fish (expressed as a percentage of non-empty stomachs) was 88% or greater in one or more of the sample periods. However, diets where the frequency of occurrence of invertebrates was greater than 90% occurred in three of the populations in one or more of the sample periods. The frequency of occurrence of invertebrates was negatively correlated with the percentage of empty stomachs, while the frequency of occurrence of fish was positively related to the percentage of empty stomachs. Invertebrate feeding was not limited exclusively to smaller pike; invertebrates were found in the stomachs of pike 24 to 60 cm long (standard length).

Trophic position scales positively with body size within but not among four species of rocky reef predators

2020 ◽  
Vol 640 ◽  
pp. 189-200 ◽  
Author(s):  
AM Olson ◽  
A Frid ◽  
JBQ dos Santos ◽  
F Juanes
Keyword(s):  
Body Size ◽  
Trophic Position ◽  
Stomach Contents ◽  
Rocky Reef ◽  
Morphometric Traits ◽  
Predator Species ◽  
Predatory Fishes ◽  
Average Size ◽  
Interspecific Comparisons ◽  
Large Predators

Intra- and interspecifically, larger-bodied predators generally occupy higher trophic positions (TPs). With widespread declines in large predators, there is a need to understand their size-based trophic roles to predict ecosystem-level responses. In British Columbia, Canada, we examined size-based trophic interactions between predatory fishes—3 rockfish species (genus Sebastes) and lingcod Ophiodon elongatus—and their prey, converting predator δ15N signatures to TP and analyzing stomach contents. Intraspecifically, TP scaled positively with predator length and gape width, but the rates of change varied by species. Interspecifically, TP did not scale positively with the observed mean sizes or known maximum sizes of species. Lingcod TP was lower than that of yelloweye and quillback rockfishes, which were 51 and 37%, respectively, smaller than lingcod. Yellowtail rockfish had the smallest average size, yet their mean TP did not differ significantly from that of lingcod. Neither species differences in some morphometric traits known to influence body size-TP relationships nor phylogenetic history explained these results. Most prey consumed were <20% of the predator’s size, which might partially explain the lack of a size-based trophic hierarchy among species. Currently, large size classes of rockfishes are being lost due to fisheries and perhaps climate-driven changes. Our findings on intraspecific size-TP relationships indicate that fishery removals of large individuals may diminish trophic structures. Interspecific comparisons of TP suggest that, along with size, species remain an important factor in understanding trophic dynamics. In addition, smaller-bodied predator species may have significant ecological roles to be considered in ecosystem-based fisheries management.

scholarly journals Abundance, Distribution, Morphometric, Feeding Evaluation and the Reproductive Strategies of Gymnarchus niloticus in the Lower River Niger at Agenebode, Edo State Nigeria

2021 ◽  
Vol 25 (8) ◽  
pp. 1371-1377
Author(s):  
M.O. Agbugui ◽  
F.E. Abhulimen ◽  
A.O. Adeniyi
Keyword(s):  
Fish Species ◽  
Standard Length ◽  
Relevant Information ◽  
Breeding Strategy ◽  
Reproductive Pattern ◽  
Maturity Stage ◽  
Major Food ◽  
Gymnarchus Niloticus ◽  
Small Brood ◽  
River Niger

The study of the numerous areas of biology of fish produces ample and relevant information that aids scientist to explore, know and maintain the survival, growth, continuity and sustainability of life of various fish species. A total of 94 specimens of Gymnarchus niloticus were collected from River Niger at Agenebode during the sample period that ranged from 14 – 94 cm total length (54.88± 17.92); weighed 424 - 2281g (1569.61 ± 422.85). The length weight relationship (LWR) of G. niloticus in this study showed a negative (b<3) allometric growth pattern. Out of the 94 specimens analysed 54 males and 40 females were examined with a ratio of 1:1.4. Insects and decapods were the major food of the juveniles of Gymnarchus niloticus while the major food of preference of the sub adults and adults were Fish and insects with 27.12%, and 27.97% by FO. Gymnarchus niloticus possesses a single ovary in the female and single testis in the male which is often referred to as unpaired gonad. Fecundity ranged between 620 to 1378 eggs with a mean of 957.69 ± 112.31 eggs in females. The relationship between fecundity (F) and weight (W) and fecundity and standard length (SL) showed that fecundity is more related to weight than length of fish. Log F = 820.66 + 0.11 W and Log F = 151.23 + 5.31 SL. Fecundity had a positive significant correlation (P<0.05) with both somatic weight (r = 0.714) and standard length (r = 0.657) of fish. Ova diameter showed a ranged between 3.5 and 7.9 mm with a mean of 4.72 ± SD1.69 mm and it had significant relationship (P<0.05) with total weight, gonad weight and maturity stage. Gymnarchus niloticus in the Lower River Niger at Agenebode showed that G. niloticus has an unpaired gonad in both sexes, a gonochoristic reproductive pattern. Fecundity is low and the ova are large. They are small brood spawners with asynchronous breeding strategy. The attributes of G. niloticus obtained from this study reveals that the fish species is a good candidate for fish culture.

scholarly journals A PRELIMINARY STUDY ON THE GROWTH AND FOOD OF STOLEPHORUS SPP. FROM THE JAKARTA BAY

2018 ◽  
Vol 14 ◽  
pp. 1-30
Author(s):  
Burhanuddin ◽  
Sularto Martosewojo ◽  
Malikusworo Hutomo
Keyword(s):  
Growth Rate ◽  
Standard Length ◽  
Stomach Contents ◽  
Size Group ◽  
Preliminary Study

The length compositions of Stolephorus heterolobus, Stolephorus insularis and Stolephorus  pseudoheterolobus  were observed. S. heterolobus ranged from 25 to 71 mm., S. insularis from 27 to 75 mm and S. pseudoheterolobus from 27 to 67 mm standard length. The  ages  of these  three  species  were estimated. The  asymptotic  length  of S. heterolobus was 97 mm attained at the age of 26 months, S. insularis 86 mm at 26 months and S. pseudohetorolobus 88 mm at 20 months. The highest growth rate of S. heterolobus was at the size group 30 - 80 mm standard length, that of S. insularis was at 30-50  mm, and that of S. insularis was observed to be the lowest. The stomach contents of S. heterolobus and S. pseudoheterolobus   were studied tand were found that the food  of these two  species  was  more or  less the  same. They fed mainly on zooplankton consisting of copepods and other crustaceans.

Size data and stomach contents of common dolphins, Delphinus delphis, near Plymouth

1986 ◽  
Vol 66 (2) ◽  
pp. 319-322 ◽  
Author(s):  
P. L. Pascoe
Keyword(s):  
Natural History ◽  
Stomach Contents ◽  
British Museum ◽  
Common Dolphin ◽  
Delphinus Delphis ◽  
South West ◽  
Seasonal Basis ◽  
The Common ◽  
Common Dolphins ◽  
Size Data

INTRODUCTIONThe laboratory at Plymouth was notified of the capture of five dolphins in a commercial trawl on 9 December 1982, three of the specimens were living and therefore immediately released. The remaining two were brought to the laboratory, identified as Delphinus delphis Linnaeus, 1758, their size and sex were recorded and the stomachs removed for examination of their contents. The exact location of capture was not recorded, but is known to be within 40 miles of Plymouth.Reports of strandings of D. delphis collected by the British Museum (Natural History), (Harmer, 1914–27; Fraser, 1934, 1946, 1953, 1974) and more recent recorded sightings (Evans, 1980) show that the common dolphin is clearly not rare in British waters. Although the species has been recorded off all British coasts, sightings and strandings are concentrated off the south and south-west coasts of Britain and Ireland. The variation in their numbers and distribution both during this century and on a seasonal basis each year has been accounted for mainly by the fluctuation and movement of their food supply (Evans, 1980; Sheldrick, 1976).

Diet of subadult Australian salmon, Arripis truttaceus, in Western Port, Victoria

1994 ◽  
Vol 45 (4) ◽  
pp. 617 ◽  
Author(s):  
FE Hoedt ◽  
WF Dimmlich
Keyword(s):  
Species Composition ◽  
Food Item ◽  
Prey Species ◽  
Stomach Contents ◽  
Size Group ◽  
Significant Component ◽  
Late Autumn ◽  
Size Groups ◽  
Seasonal Basis ◽  
Autumn And Winter

Stomach contents from 285 pelagically feeding Australian salmon (Arripis truttaceus) caught in Western Port, Victoria, between May 1992 and June 1993 were examined. Stomach contents consisted of three species of clupeoid fishes. These were, in order of importance, anchovy (Engraulis australis), pilchard (Sardinops neoplchardus) and sandy sprat (Hyperlophus vittatus). The diet of A. truttaceus varied on a seasonal basis, both in terms of prey species composition and prey age (juvenile or adult). Adult anchovy were the dominant food item between October and January. In May 1992 and in February and March 1993, juvenile clupeoids dominated gut samples, with most of these being anchovy and pilchard. Sandy sprat comprised a significant component of gut samples in May 1992 and June 1993. Two size groups of salmon were temporarily resident in Western Port. The largest salmon were caught in October and November, and these were replaced by a smaller size group that dominated catches between December and June. The arrival of A. truttaceus subadults in Western Port in spring and their gradual departure from the bay in the late autumn and winter appears to be closely tied to the seasonal inshore/offshore migrations of prey species.

Diets of commercially exploited fish from Bass Strait and adjacent Victorian Waters, south-eastern Australia

1984 ◽  
Vol 35 (5) ◽  
pp. 549 ◽  
Author(s):  
N Coleman ◽  
M Mobley
Keyword(s):  
Stomach Contents ◽  
Relative Importance ◽  
Food Items ◽  
South Eastern ◽  
Major Food ◽  
Eastern Australia ◽  
Commercial Species ◽  
Index Of Relative Importance ◽  
South Eastern Australia

Stomach contents were analysed to investigate the diets of 52 commercial species of fish. Fish were collected from Bass Strait and adjacent Victorian waters, south-eastern Australia; samples effectively covered the whole of the Victorian coast. Particular emphasis was placed on estimating the importance of arrow squid, Nototodarus gouldri in the diets of the species investigated. For most of the species investigated, the major food items (expressed as the proportion of stomach contents by number, weight and volume or through the calculation of the Index of Relative Importance) were fish or crustaceans. Cephalopods were found in the diets of 21 species but provided a major proportion of the stomach contents in only six species. Arrow squid did not appear to be a major item in the diets of any of the species investigated. For those species that eat large amounts of cephalopods, it appears to be octopus, rather than squid, that is of most significance in the diet.

Observations on the biology of tarpon, Megalops cyprinoides (Broussonet) (Pisces : Megalopidae), in the Sepik River, Northern Papua New Guinea

1987 ◽  
Vol 38 (4) ◽  
pp. 529 ◽  
Author(s):  
D Coates
Keyword(s):  
Papua New Guinea ◽  
Standard Length ◽  
Seasonal Changes ◽  
Stomach Contents ◽  
Higher Order ◽  
Small Fish ◽  
Surplus Energy ◽  
Preferred Habitat ◽  
Sepik River ◽  
Terrestrial Insects

M. cyprinoides was recorded in higher-order rivers, ox-bow lakes and other areas of permanent water and also on the floodplain, although this is not a preferred habitat. Juveniles enter the river in April to July and the fish return to the sea before they begin to mature. The smallest individual recorded was 103 mm, the largest 440 mm (standard length). Fat deposit index was low for the whole population and surplus energy is probably directed to growth and not stored. Condition and fat deposit index were both slightly, but significantly, lower during the dry season. Stomach contents showed that this species is a meso-predator, feeding mainly on small prawns, aquatic and terrestrial insects and small fish. No major seasonal changes in diet were evident.

scholarly journals Biology of non-native species (Rhaphiodon vulpinus Agassiz, 1829) (Characiformes, Cynodontidae) in a cage fish farm area, Upper Paraná River Basin, Brazil

2019 ◽  
Vol 31 ◽  
Author(s):  
Aymar Orlandi Neto ◽  
Lidiane Franceschini ◽  
Letícia de Oliveira Manoel ◽  
Rosicleire Veríssimo-Silveira ◽  
Rosilene Luciana Delariva ◽  
...  
Keyword(s):  
Standard Length ◽  
Native Species ◽  
Diet Composition ◽  
Feeding Activity ◽  
Gravimetric Method ◽  
Stomach Contents ◽  
Fish Farm ◽  
Small Fish ◽  
Intensity Of Infection ◽  
Cage Fish

Abstract Aim To assess the dietary, populational and parasitological aspects of the non-native wild species Rhaphiodon vulpinus in an area under the influence of cage fish farm, in the Ilha Solteira Reservoir, São Paulo State. Methods Fifty-one specimens of R. vulpinus were captured bimonthly, from September 2014 to August 2016, with gill nets with different mesh sizes, in area surrounding a cage fish farm and area not influenced by this activity. The specimens were quantified and their mass (g) and standard length (cm) measured. The stomachs were analyzed with a stereomicroscope and the food items were quantified using the gravimetric method. The parasites were collected during necropsy and their prevalence, mean intensity of infection and mean abundance were subsequently calculated. Results There were changes in feeding activity regarding the area, with greater numbers of individuals with stomach contents in the areas under the influence of fish farm. However, diet composition did not change between the areas analyzed, with prey represented by small fish, such as Geophagus sveni, and shrimps. In the fish farm area there was also a decrease in abundance and an increase in the total mass of the individuals, while there was no difference in standard length between the areas. In terms of parasitological aspects, low parasitic indexes and the absence of differences between the areas were observed. The first report of the monogenean Notozothecium lamotheargumedoi in the Ilha Solteira reservoir is also presented. Conclusions The cage fish farm affected some aspects of the population and the food intake of R. vulpinus. Furthermore, the parasite-host relationship demonstrated that phylogenetic specificities had a greater effect than aquaculture activity on R. vulpinus in the fish farm area.

scholarly journals An osteometric approach to reconstruct the length and weight of Lutjanus argentiventris (Perciformes: Lujtanidae) for archaeological and ecological purposes

2020 ◽  
Vol 18 (3) ◽  
Author(s):  
María Fernanda Martínez-Polanco ◽  
Philippe Béarez
Keyword(s):  
Standard Length ◽  
Strong Correlation ◽  
Historical Ecology ◽  
Stomach Contents ◽  
Eastern Pacific ◽  
Fresh Weight ◽  
Allometric Model ◽  
Total Length ◽  
Wide Range ◽  
Total Fresh Weight

ABSTRACT Lutjanus argentiventris presents a large intertropical distribution within the Eastern Pacific, which is as important to fisheries now as it was in the pre-Hispanic period. The purpose of this article is to present an allometric model that enables the size and weight of L. argentiventris to be predicted, using the isolated bones found in archaeological and paleontological contexts or the stomach contents of ichthyophagous species. A modern collection of L. argentiventris from Ecuador was used, composed of 37 individuals covering a wide range of sizes and weights. The total length (TL), standard length (SL), and total fresh weight (W) of each individual was gathered. The TL of the sample ranged between 210 and 760 mm, the SL between 164 and 627 mm and the W ranged between 123 and 6550 g. The most frequent bones (15) and otoliths were chosen and 39 measurements were taken. The total length-weight relationship was W = 6E-06 TL3.1513 with R 2 = 0.997. In general, it was observed that the relationships between the TL and the bone measurements had a strong correlation (R² > 0.95). The allometric model will be useful not only for archaeologists but also for biologists working on historical ecology.

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