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.

Aspects of the Biology of the Perchlet Ambassis interrupta Bleeker (Pisces: Ambassidae) in the Sepik River, Papua New Guinea

1990 ◽  
Vol 41 (2) ◽  
pp. 267 ◽  
Author(s):  
D Coates
Keyword(s):  
Papua New Guinea ◽  
Standard Length ◽  
Aquatic Insect ◽  
New Guinea ◽  
River Channels ◽  
Insect Larvae ◽  
Transient Nature ◽  
Sepik River ◽  
Mean Diameter ◽  
Aquatic Insect Larvae

Ambassis interrupta enters the lower Sepik River and is found in or near turbid river channels. The species is considered to be a predominantly marine and/or estuarine spawner. A. interrupta feeds mainly on small aquatic insect larvae but also on insects from terrestrial sources and on small crustaceans. Low variability in the data for condition, fat deposition, reproduction and feeding is interpreted by the species' lack of affinity for the floodplain and the presumed transient nature of the population. Fecundity (F) is expressed by the formula F= - 12.3 + I5.3, where I is standard length (mm), and varied between 29 000 and 310 000 eggs per fish (70-105 mm standard length). Eggs are small (0.22 mm mean diameter) in comparison with known egg sizes for freshwater-spawning ambassids.

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.

Sediment export from the Sepik River, Papua New Guinea: evidence for a divergent sediment plume

2000 ◽  
Vol 20 (16) ◽  
pp. 2239-2266 ◽  
Author(s):  
G.C Kineke ◽  
K.J Woolfe ◽  
S.A Kuehl ◽  
J.D Milliman ◽  
T.M Dellapenna ◽  
...  
Keyword(s):  
Papua New Guinea ◽  
New Guinea ◽  
Sepik River ◽  
Sediment Export

scholarly journals Temporal and ontogenetic variations in feeding habits of Hollandichthys multifasciatus (Teleostei: Characidae) in coastal Atlantic rainforest streams, southern Brazil

2009 ◽  
Vol 7 (3) ◽  
pp. 415-420 ◽  
Author(s):  
Vinícius Abilhoa ◽  
Hugo Bornatowski ◽  
Gislaine Otto
Keyword(s):  
Quantitative Methods ◽  
Feeding Habits ◽  
Atlantic Rainforest ◽  
Small Fish ◽  
Fish Feed ◽  
Southern Brazil ◽  
Qualitative And Quantitative ◽  
Qualitative And Quantitative Methods ◽  
Black Water ◽  
Terrestrial Insects

Feeding habits of the characin Hollandichthys multifasciatus were investigated. Samplings were made between March 2004 and February 2005 in two black water streams of the coastal Atlantic rainforest in southern Brazil. The diet, evaluated by qualitative and quantitative methods, included aquatic and terrestrial insects, decapods, oligochaetes, plants and spiders. Large individuals feed mainly on plants, terrestrial insects, and spiders, whereas small fish feed basically on plants and oligochaetes. The species showed an omnivorous feeding habit, and its diet was composed of autochthonous (mainly oligochaetes) and allochthonous (plants and terrestrial insects) material.

scholarly journals Scaling the feeding mechanism of the largemouth bass (Micropterus salmoides): motor pattern

1995 ◽  
Vol 198 (5) ◽  
pp. 1161-1171 ◽  
Author(s):  
P Wainwright ◽  
B Richard
Keyword(s):  
Body Size ◽  
Largemouth Bass ◽  
Standard Length ◽  
Prey Capture ◽  
Micropterus Salmoides ◽  
Motor Pattern ◽  
Onset Time ◽  
Small Fish ◽  
Scaling Effects ◽  
Emg Signal

We present the first analysis of scaling effects on the motor pattern of a feeding vertebrate. Data are presented for the effects of body size on the pattern of activity in four head muscles during prey capture in the largemouth bass, Micropterus salmoides. Electromyographic (EMG) recordings were made from three expansive-phase muscles (the epaxialis, the sternohyoideus and the levator arcus palatini) and one compressive-phase muscle (the adductor mandibulae), during the capture of small fish prey. Recordings were made of 181 prey-capture events from 19 bass that ranged in size from 83 to 289 mm standard length. We measured seven variables from the myogram of each capture to quantify the temporal pattern of muscle activation, including the duration of activity in each muscle and the onset time of each muscle, relative to the onset of the sternohyoideus muscle. Regressions of the mean value of each variable for the 19 individuals on standard length revealed that only the onset time of the adductor mandibulae changed with fish body size. The increase in onset time of the adductor muscle appears to reflect the longer time taken to open the mouth fully in larger fish. Other research shows that the kinematics of the strike in this species slows significantly with increasing body size. The combined results indicate that the duration of the EMG signal is not directly correlated with the duration of force production in muscles when compared between fish of different sizes. The lack of scaling of burst duration variables suggests that the reduced speeds of prey-capture motion are explained not by changes in the envelope of muscle activity, but rather by the effects of scale on muscle contractile kinetics. These scaling effects may include changes in the relative resistance of the jaw and head structures to movement through water and changes in the intrinsic contractile properties of the muscles of the feeding apparatus.

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.

scholarly journals Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

2009 ◽  
Vol 7 (4) ◽  
pp. 701-708 ◽  
Author(s):  
Ana Paula Vidotto-Magnoni ◽  
Edmir Daniel Carvalho
Keyword(s):  
Aquatic Insects ◽  
Food Resource ◽  
Gravimetric Method ◽  
Stomach Contents ◽  
Food Resources ◽  
Food Category ◽  
Main Food ◽  
Tietê River ◽  
Two Samples ◽  
Terrestrial Insects

We evaluated the feeding of fish species of the Nova Avanhandava Reservoir, low Tietê River, São Paulo State, Brazil. Fishes were collected in two stretches of the reservoir: Santa Bárbara (14 samples) and Bonito (two samples) between September 2002 and March 2004, using gill and seining nets. The results of stomach contents analysis were expressed with the frequency of occurrence and gravimetric method, combined in the Alimentary Index (AI). The 20 species studied consumed 52 food items, grouped in 10 food categories: aquatic insects, terrestrial insects, crustaceans, fish, macroinvertebrates, microcrustaceans, algae, vegetal matter, detritus/sediment and scales. The aquatic insects (mainly Chironomidae, Odonata and Ephemeroptera) were the most common food resources, consumed by 18 species. The diet composition of the community (species grouped) indicated that the dominant food category in the diet of fishes was aquatic insects (AI = 77.6%), followed by crustaceans (AI = 7.1%). Four trophic guilds were identified according a cluster analysis (Pearson distance): insectivorous (10 species), omnivorous (4 species), detritivorous (3 species) and piscivorous/carcinophagous (3 species). Despite the highest number of species, the insectivorous guild was responsible for more than 80% in captures in number and biomass (CPUEn and CPUEb). The low values of niche breadth presented by all species, along with the low values of diet overlap between species pairs indicate a high degree of food resources partitioning among species. The aquatic insects, despite being the main food resource of insectivorous fishes, also complemented the diet of other species, which demonstrate the importance of this food resource for the fish community, sustaining a high diversity, abundance and biomass of fishes.

Some chemical features of two Papuan fresh waters (Papua New Guinea)

1976 ◽  
Vol 27 (3) ◽  
pp. 467 ◽  
Author(s):  
T Petr
Keyword(s):  
River Water ◽  
Papua New Guinea ◽  
Chemical Weathering ◽  
New Guinea ◽  
Tropical River ◽  
Dominant Source ◽  
Sepik River ◽  
The World ◽  
Port Moresby ◽  
Total Salinity

The Purari River in Papua (Papua New Guinea) is a tropical river with ionic dominance similar to that of the world average river water, i.e. Ca > Mg > Na > K, and HCO3 > (SO4?) > Cl. As the sulphate concentration was not determined, the anionic trend still needs to be further investigated. The Na:Ca as well as the Ca + Mg:Na + K ionic ratios suggest that chemical weathering in the highlands is the dominant source of dissolved solids, and that it determines the chemistry of the lower course of the Purari River. Among the waters investigated, the Purari River, in its lower course, has a total salinity higher than that of the Sirinumu impoundment, and lower than that of the Sepik River. The low concentration of solutes in the Sirinumu impoundment near Port Moresby indicates that oligotrophication can be expected in reservoirs built on Papuan rivers.

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