scholarly journals Comparative assessment of age, growth and food habit of the black-chinned tilapia, Sarotherodon melanotheron (Rüppell, 1852), from a closed and open lagoon, Ghana

2019 ◽  
Vol 22 (1) ◽  
Author(s):  
Cephas Kwesi Zuh ◽  
Seth Mensah Abobi ◽  
Benjamin Betey Campion
Keyword(s):  
Content Analysis ◽  
Stomach Content ◽  
Food Item ◽  
Stomach Content Analysis ◽  
Reference Points ◽  
Fish Populations ◽  
Von Bertalanffy ◽  
Total Length ◽  
Fish Samples ◽  
Sarotherodon Melanotheron

Abstract Background The black-chinned tilapia, Sarotherodon melanotheron, is the most abundant fish species in the Nakwa (an open lagoon) and Brenu (a closed lagoon) in the Central Region of Ghana. Aspects of the life history characteristics and the ecology of the fish populations in both lagoons were studied to assess the bio-ecological status of this important resource. Methods Fish samples were obtained from fishermen that fish on the Nakwa and Brenu lagoons using cast, drag and gill nets. The age of the fish was assessed from otoliths analysis and its growth modelled following the von Bertalanffy growth function. Morphometric characteristics of the fish populations were analysed using power regression and ANOVA for parameters comparisons, and Student’s t test to determine whether species grew isometrically. The percentage occurrence method was used to analyse the stomach contents of the fish. Results A total of 382 fish samples from both lagoons were measured, comprising 209 from Nakwa lagoon and 176 from Brenu lagoon. The size and weight of fish samples ranged between 3.9–11.5 cm total length and 1.0–27.3 g for Nakwa Lagoon and 5.6–12.8 cm total length and 3.2–29.8 g for the Brenu Lagoon. The estimated von Bertalanffy growth parameters were L∞ = 12.04 cm and K = 2.76/year for the Nakwa Lagoon samples and L∞ = 13.44 cm and K = 3.27/year for Brenu Lagoon samples. Daily otolith incremental rate ranged from 0.01–0.03 mm per day to 0.01–0.02 mm per day for Nakwa and Brenu lagoons, respectively. Stomach content analysis of the fish samples revealed that the species are planktivorous and the range of food varied between the lagoons. Green algae were the most prevalent food item in the stomachs of the fish samples from Nakwa with the frequency of 69% whilst diatoms (80.5%) were most prevalent phytoplanktonic food item for the fish in Brenu lagoon. Conclusions The estimates of asymptotic length for the species in both lagoons are close to known values of the species length at first sexual maturity and points to intensive fishing pressure. As a consequence, a comprehensive sample-based survey is required in both lagoons to derive estimates of management reference points. The results of the stomach content analysis are beneficial to the construction of diet matrix for ecosystem models of the two systems.

scholarly journals Comparative Assessment of Age, Growth and Food Habit of the Black-Chinned Tilapia, Sarotherodon melanotheron (Rüppell, 1852), from Closed and Open Lagoons, Ghana

2019 ◽  
Author(s):  
Cephas Kwesi Zuh ◽  
Seth Mensah Abobi ◽  
Benjamin Betey Campion
Keyword(s):  
Food Item ◽  
Growth Parameters ◽  
Ecological Status ◽  
Food Habit ◽  
Stomach Content Analysis ◽  
Von Bertalanffy ◽  
Fish Samples ◽  
Incremental Rate ◽  
Management Policies ◽  
Sarotherodon Melanotheron

The black-chinned tilapia Sarotherodon melanotheron is the most abundant fish species in the Nakwa (a closed lagoon) and Brenu (an open lagoon) in the Central region of Ghana. Aspects of the life history characteristics and the ecology of the fish populations in both lagoons were studied to assess the bio-ecological status of this important resource. The estimated von Bertalanffy growth parameters were L∞ = 12.04 cm; K =2.76 year-1 for the Nakwa Lagoon samples and L∞ = 13.44 cm; K = 3.27 years-1 for Brenu Lagoon samples. Daily otolith incremental rate ranged from 0.01-0.03mm per day and 0.01-0.02mm per day for Nakwa and Brenu lagoons respectively. Stomach content analysis of the fish samples revealed that the species are planktivorous and the range of food varied between the lagoons. Green algae was the most prevalent food item in the stomachs of the fish samples from Nakwa with frequency of 69% while diatoms (80.5%) were most prevalent phytoplanktonic food item in for the fish in Brenu lagoon. The results of this study of Sarotherodon melanotheron from the two lagoons and can be used to improve on management policies, maximize yield and to sustain the fishery resources.

scholarly journals Stomach Content, Length-weight Relationship and Condition Factor of Tilapia spp. found in the Sombreiro River across Three Communities in Rivers State, Nigeria

2019 ◽  
pp. 1-14
Author(s):  
E. O. Horsfall ◽  
G. M. Sokari ◽  
M. Moslen ◽  
I. K. E. Ekweozor
Keyword(s):  
Content Analysis ◽  
Stomach Content ◽  
Physicochemical Parameters ◽  
Condition Factor ◽  
Stomach Content Analysis ◽  
Weight Relationship ◽  
Significant Difference ◽  
Fish Samples ◽  
Rivers State ◽  
Sarotherodon Melanotheron

Aim: The present study aims to determine the condition factor incomplete of Tilapia guineensis and Sarotherodon melanotheron in Sombreiro River across Buguma, Abonnema and Degema communities in Rivers State. Study Design: This study employs fieldwork, laboratory experimental design, statistical analysis and interpretation of data. Place and Duration of Study: Live fish samples were caught by fishermen in Buguma, Abonnema and Degema communities in Kalabari kingdom of Rivers State, and were conveyed in a rectangular plastic aquarium containing ice blocks and oxygen bags to the department of Applied and Environmental Biology, Rivers State University. The duration of the study lasted for twelve weeks (65 days). Methodology: One hundred and eighty fish samples give their average weights and lengths were identified. The fish samples were weighed using an electronic weighing balance, the total length and length of intestine were measured with a meter rule (cm), color of fish, spines and rays of fish were also observed. Their stomach contents were analyzed viewing under a microscope. The frequency of occurrence method and the numerical method were used for analyzing the food items. Results: The stomach content analysis indicated that the major food was phytoplankton. The length and weight relationship in the three sampled stations for T. guineensis and Sarotherodon melanotheron showed negative allometric growth, (<3).  The condition factor for all the fish samples was greater than one. The physicochemical parameters showed that there were significant differences in the various physicochemical parameters across the study stations except for turbidity (P=0.744) and salinity (P=0.922), that showed no significant difference across the study stations. Conclusion: The length-weight relationship in fishes can be affected by a number of factors including season, habitat, gonad maturity, sex, diet, stomach fullness, health and differences in length ranges of the specimen caught. The exact relationship between length and weight differs among species of fish according to their inherited body shape, and within a species according to the condition (robustness) of individual fish. The stomach content analysis of the sampled fishes provided a baseline study of food and feeding habits of Tilapia species in the sampled stations.

scholarly journals Diet of Leptobotia elongata revealed by stomach content analysis and inferred from stable isotope signatures

2015 ◽  
Vol 98 (8) ◽  
pp. 1965-1978 ◽  
Author(s):  
L. Li ◽  
Q. Wei Wei ◽  
J. Ming Wu ◽  
H. Zhang ◽  
Y. Liu ◽  
...  
Keyword(s):  
Content Analysis ◽  
Stable Isotope ◽  
Stomach Content ◽  
Stomach Content Analysis ◽  
Stable Isotope Signatures

Functional morphology of the mouthparts and proventriculus of the rock crab Nectocarcinus tuberculosus (Decapoda: Portunidae)

2003 ◽  
Vol 83 (4) ◽  
pp. 821-834 ◽  
Author(s):  
Indra Raymond Salindeho ◽  
Danielle Jane Johnston
Keyword(s):  
Content Analysis ◽  
Stomach Content ◽  
Stomach Content Analysis ◽  
Distal Region ◽  
Proximal Region ◽  
Rocky Shores ◽  
Brachyuran Crab ◽  
Cardiac Stomach ◽  
Dietary Preferences ◽  
Sea Grass

Mouthpart and proventriculus structure of the brachyuran crab Nectocarcinus tuberculosus was described by scanning electron microscopy and histology and characteristics indicative of dietary preferences were identified. A qualitative stomach content analysis was conducted to verify structural interpretations with respect to diet. The mouthparts and proventriculus of N. tuberculosus have features that are typical of macrophagous crabs and are consistent with a carnivorous diet of hard items. However, the mandibular arrangement indicates that N. tuberculosus is also adapted to ingest soft plant material and fleshy items, revealing that this crab is omnivorous which is consistent with its habitat of rocky shores and sea grass beds. Carnivorous features of the feeding apparatus include large crista dentata on the third maxillipeds that grip food items during ingestion and cuspidate setae on the second maxillipeds and first maxillae. Nectocarcinus tuberculosus has a complex arrangement of proventricular ossicles, 5-denticulated accessory teeth, and a spiny cardio-pyloric valve with rough, calcified protuberances. It has a robust, strongly calcified gastric mill with a prominent anterior cusp and 11 roughly surfaced vertical ridges on each lateral tooth specialized for crushing and grinding. In contrast to true carnivorous crabs, the mandibles in this species are symmetrically arranged, with two sharp cutting edges and no teeth, an arrangement adapted to cut softer plant-like materials and flesh. Structural interpretations with respect to diet were confirmed by stomach content analysis where items identified included gastropods, bivalves and the sea grass Posidonia australis. Functionally, the filtering system in the proventriculus of N. tuberculosus is complex. The cardiac stomach has a well developed ventral filtration system or ‘cardiac filter’ which comprises coarse and fine filters. Different modifications of setation between the distal and proximal regions of the inner valve of the pyloric filter are unique to this crab species, with an intersetule width 600 nm in the distal region and 80–100 nm in the proximal region. This suggests that some differentiation in filtration occurs between regions within the pyloric filter.

scholarly journals ANALISIS ISI LAMBUNG IKAN CAKALANG (Katsuwonus pelamis) DAN IKAN MADIDIHANG (Thunnus albacares) YANG DIDARATKAN DI BITUNG, SULAWESI UTARA

2017 ◽  
Vol 14 (2) ◽  
pp. 227
Author(s):  
Siti Mardlijah
Keyword(s):  
Content Analysis ◽  
Stomach Content ◽  
Sampling Site ◽  
Stomach Content Analysis ◽  
Small Scale ◽  
Thunnus Albacares ◽  
Dietary Composition ◽  
Skipjack Tuna ◽  
Katsuwonus Pelamis ◽  
North Sulawesi

Penelitian ini telah dilakukan terhadap isi lambung ikan cakalang (Katsuwonus pelamis) hasil tangkapan pole and line dan ikan madidihang (Thunnus albacares) hasil tangkapan hand line yang didaratkan di Bitung, Sulawesi Utara pada bulan Mei, Juli, dan September 2005. Penelitian ini bertujuan untuk mengetahui komposisi jenis makanan ikan cakalang (Katsuwonus pelamis) dan ikan madidihang (Thunnus albacares). Contoh ikan cakalang (Katsuwonus pelamis) berjumlah 69 ekor dan contoh ikan madidihang (Thunnus albacares) berjumlah 63 ekor. Pengambilan contoh dilakukan di perusahaan perikanan dan tempat pengasapan atau fufu cakalang. Pengamatan dilakukan secara visual dan gravimetrik kemudian dianalisis dengan metode indeks of preponderance. Hasil penelitian menunjukkan bahwa komposisi makanan ke-2 jenis ikan pelagis besar tersebut berubah-ubah dan memiliki kemiripan terhadap 1 jenis makanan yaitu ikan malalugis (Decapterus macarellus), yang merupakan makanan utama ikan cakalang (Katsuwonus pelamis) dan ikan madidihang (Thunnus albacares). Stomach content analysis of skipjack tuna (Katsuwonus pelamis) which was caught by pole and line and yellow fin tuna (Thunnus albacares) caught by hand line, landed in Bitung, North Sulawesi i May, July, and September 2005 were conducted. The objective of the experiment is to know dietary composition of skipjack tuna (Katsuwonus pelamis) and yellow fin tuna (Thunnus albacares). The number of specimen observed 69 of skipjack tunas (Katsuwonus pelamis) and 63 of yellow fin tunas (Thunnus albacares). Sampling site were located in fishery company and at a small scale fish smoked industry. Stomach content analysis of the two fishes were observed visually measured and gravimetrically. The stomach content analysis was analysed based on indeks of preponderance) method. Result shows, the stomach content of skipjack tuna (Katsuwonus pelamis) and yellow fin tuna (Thunnus albacares) related changes and similar among one species are scad mackerel fishes (Decapterus macarellus). Therefore, scad mackerel fishes (Decapterus macarellus) is the dominant food for both skipjack tuna (Katsuwonus pelamis) and yellow fin tuna (Thunnus albacares).

scholarly journals EVALUATION OF ECOLOGICAL IMPORTANCE OF MYSIDS AS A FOOD ITEM IN THE DIET OF FISH, NEW ZEALAND

2015 ◽  
Vol 4 (3) ◽  
pp. 35-41
Author(s):  
N. N. Punchihewa
Keyword(s):  
Content Analysis ◽  
Fish Species ◽  
Food Item ◽  
Stomach Contents ◽  
Gut Content Analysis ◽  
Gut Content ◽  
Isotopic Study ◽  
Fish Samples ◽  
Significant Enrichment ◽  
Ecological Importance

The main objective of this study is to determine the ecological importance of mysids as a food item of selected fish species using C and N isotopes (stable isotopic study) and gut content analysis of fish. Fish samples (Galaxias maculates and Athrinidae sp.) and mysid samples (Tenagomysis chiltoni and T. novaezealandiae) were collected from Kakamatua Stream situated on the west coast of Auckland region in late January 2009 (summer). All the collected samples were oven-dried, and then ground to obtain a homogeneous powder. Three replicates of each sample were prepared. Samples were processed by the Waikato Stable Isotope Unit (Scientific/20). For gut content analysis, ten specimens of each fish species, G. maculates and Athrinidae sp. were collected and were fixed in 5% formalin immediately. These fish specimens were dissected out and the stomach contents were mixed in a beaker with 10 ml water. After mixing, the contents were examined under the light microscope fitted with an eye piece micrometer. It is evident from both methods that two mysid species T. chiltoni and T. novaezealandiae form a substantial component of the diet of commercially important G. maculates, at Kakamatua stream. Changes in the diet, during the ontogenetic development, in relation to body size have shown a significant enrichment of ?15N values and ?13C values of T. chiltoni and G. maculates.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 35-41

Technique for Tagging Small Fish with I131 for Evaluation of Predator–Prey Relationships

1978 ◽  
Vol 35 (1) ◽  
pp. 143-145 ◽  
Author(s):  
Gerard J. FitzGerald ◽  
Miles H. A. Keenleyside
Keyword(s):  
Content Analysis ◽  
Key Words ◽  
Stomach Content ◽  
Stomach Content Analysis ◽  
Small Fish ◽  
Short Term ◽  
Predator Prey ◽  
Cichlasoma Nigrofasciatum ◽  
Quantitative Studies ◽  
Convict Cichlids

Experiments to test the feasibility of using radioactive I131 as a technique for evaluation of conspecifïc predation on fry by adult convict cichlids (Cichlasoma nigrofasciatum) are described. The technique is useful for short-term quantitative studies of predator–prey interactions where it is not possible to observe and quantify predation directly or where stomach content analysis of adults is not feasible. Key words: radioactive tagging, predator–prey interactions, Cichlasoma nigrofasciatum

scholarly journals Feeding habits of the Cichlid Chromidotilapia guntheri (Sauvage, 1882) in some hydrosystems of Ivory Coast

2018 ◽  
Vol 6 (1) ◽  
pp. 18
Author(s):  
Charles Koffi BOUSSOU ◽  
Gustave N’guessan ALIKO ◽  
Mexmin Koffi KONAN ◽  
Felix Koffi KONAN
Keyword(s):  
Content Analysis ◽  
Stomach Content ◽  
Ivory Coast ◽  
Feeding Habits ◽  
Feeding Strategy ◽  
Stomach Content Analysis ◽  
Trophic Niche ◽  
Feeding Habit ◽  
Ontogenetic Shift ◽  
It Practices

The feeding habit of Chromidotilapia guntheri was investigated in seven hydrosystems of Ivory Coast. The contents of 156 non-empty stomachs were examined from specimens caught in the rivers Soumié, Eholié, Noé, Ehania and Banco, the Bea rill and the Kpoda lake. Diets composition, feeding strategy and trophic niche width were analyzed among hydrosystems. Stomach content analysis indicated that C. guntheri feeds preferentially on plants and insects debris and secondarily, it consumed insects’ larvae, nymphs and adults in all habitats. This species would be an omnivorous with a detritivorous tendency. As feeding strategy, it practices a generalist strategy even if some individuals displayed specialization intentions on insects at different stages of metamorphosis. Investigations on ontogenetic shift revealed that juveniles and adults of C. guntheri consume substantially the same types of prey with varying amounts depending on the size of the fish. However there is a significant decrease in the proportions of gastropods and oligochaetes ingested when growing.

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