scholarly journals ASPEK BIOLOGI HASIL TANGKAPAN PANCING ULUR PADA RUMPON PORTABLE

2019 ◽  
Vol 11 (2) ◽  
pp. 399-412
Author(s):  
Mulyono S Baskoro ◽  
Roza Yusfiandayani ◽  
Sutia Yuningsih

Rumpon portable merupakan rumpon yang tidak diletakkan secara tetap di perairan, tetapi diletakkan pada saat akan melakukan kegiatan penangkapan ikan. Tujuan dari penelitian ini adalah mengidentifikasi tingkat kematangan gonad, menganalisis hubungan isi perut hasil tangkapan dengan kelimpahan plankton yang tertarik pada rumpon portable, menganalisis indeks keanekaragaman, keseragaman, dan dominan plankton yang terdapat pada isi perut ikan dengan plankton yang terdapat pada perairan, menganalisis trofik level jenis ikan di sekitar rumpon portable. Metode penelitian dilakukan dengan cara experimental fishing dan uji laboratorium. Analisis data yang digunakan dalam penelitian ini yaitu analisis tingkat kematangan gonad, stomach content analysis, indeks keanekaragaman, indeks keseragaman dan indeks dominansi, serta analisis trofik level. Total hasil tangkapan ikan sebanyak 165 ekor didominasi oleh jenis ikan kembung dan ikan tongkol. Ikan-ikan lainnya yang tertangkap yaitu jenis ikan todak, barakuda dan selar kuning. Hasil analisis menunjukkan bahwa hasil tangkapan didominasi oleh ikan dengan TKG II sebanyak 53%, dan disusul ikan dengan TKG I sebanyak 38% dari total hasil tangkapan. Ikan-ikan yang tertangkap pada penelitian ini terdiri dari ikan pemakan plankton atau plankton feeders dan ikan karnivora. Organisme yang ditemukan dalam isi perut ikan yaitu ikan kecil, cumi-cumi, fitoplankton yang terdiri dari 7 genus, serta beberapa genus dari zooplankton. Hasil tangkapan ikan terbanyak ditangkap pada pengamatan hari ke-2 dengan jumlah tangkapan sebanyak 34 ekor.

2015 ◽  
Vol 98 (8) ◽  
pp. 1965-1978 ◽  
Author(s):  
L. Li ◽  
Q. Wei Wei ◽  
J. Ming Wu ◽  
H. Zhang ◽  
Y. Liu ◽  
...  

Author(s):  
Indra Raymond Salindeho ◽  
Danielle Jane Johnston

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.


2017 ◽  
Vol 14 (2) ◽  
pp. 227
Author(s):  
Siti Mardlijah

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).


2019 ◽  
Vol 22 (1) ◽  
Author(s):  
Cephas Kwesi Zuh ◽  
Seth Mensah Abobi ◽  
Benjamin Betey Campion

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.


1978 ◽  
Vol 35 (1) ◽  
pp. 143-145 ◽  
Author(s):  
Gerard J. FitzGerald ◽  
Miles H. A. Keenleyside

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


2018 ◽  
Vol 6 (1) ◽  
pp. 18
Author(s):  
Charles Koffi BOUSSOU ◽  
Gustave N’guessan ALIKO ◽  
Mexmin Koffi KONAN ◽  
Felix Koffi KONAN

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.


2020 ◽  
Vol 39 (8) ◽  
pp. 53-61
Author(s):  
Dongyan Han ◽  
Chongliang Zhang ◽  
Ying Xue ◽  
Binduo Xu ◽  
Yiping Ren ◽  
...  

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