scholarly journals LUAS RELUNG DAN KOMPETISI PAKAN KOMUNITAS IKAN DI SITU PANJALU, JAWA BARAT

2017 ◽  
Vol 3 (3) ◽  
pp. 159
Author(s):  
Astri Suryandari ◽  
Kunto Purnomo
Keyword(s):  
Oreochromis Niloticus ◽  
Fish Community ◽  
Niche Breadth ◽  
Mesh Size ◽  
Stock Enhancement ◽  
Competition Index ◽  
Gill Net ◽  
Amphilophus Citrinellus ◽  
Food Niche

Penelitian ini bertujuan untuk mempelajari luas relung dan kompetisi komunitas ikan di Situ Panjalu. Pengambilan contoh ikan dilakukan pada bulan Mei dan September 2008 denganmenggunakan jaring insang berukuran 2,5; 3,0; dan 3,5 inci. Komunitas ikan di Situ Panjalu terdiri atas ikan nila (Oreochromis niloticus), kongo (Parachromis managuensis), oskar (Amphilophus citrinellus), golsom (Aequidens goldsom), selebra (Amphilopus sp.), dan keril (Aequidens rivulatus). Berdasarkan atas analisis luas relung dan kompetisi pakan, ikan golsom mempunyai potensi untuk berkembang menjadi populasi yang besar di perairan Situ Panjalu dibandingkan jenis ikan lain.Relung pakan yang dapat dioptimalkan adalah fitoplankton sehingga untuk pengkayaan stok dapat dilakukan melalui penebaran ikan herbivora pemakan plankton. The aim of the research was to identified niche breadth and competition among of fishes community in Situ Panjalu. Samples were collected by gill net of 2.5; 3.0; and 3.5 inches mesh size in Mei and September 2008. Fish community in Panjalu consist of tilapia (Oreochromis niloticus), kongo (Parachromis naguensis), midas cichlid (Amphilopus citrinellus), golsom (Aequidens goldsom), selebra (Amphilophus sp.) and keril (Aequidens rivulatus). Based on niche breadth and competition index, goldsom is potentially growth into great population compare to another fishes species in Panjalu. Food niche that could be optimimized was phytoplankton so that stock enhancement could be conducted by stocking the herbivorous fishes feed on phytolankton.

Aspects of the fishery, maturation and net selectivity of the wedge sole (Dicologoglossa cuneata) off south-western Iberia: implications for fishery management

2009 ◽  
Vol 90 (7) ◽  
pp. 1465-1474 ◽  
Author(s):  
Miguel Neves Santos ◽  
Pedro Gil Lino
Keyword(s):  
Fishery Management ◽  
River Mouth ◽  
Mesh Size ◽  
Scientific Basis ◽  
Catch Per Unit Effort ◽  
Important Species ◽  
Gill Net ◽  
Catch Rates ◽  
Log Normal ◽  
First Maturity

The wedge sole (Dicologoglossa cuneata, Moreau 1881) is a commercially important species for the artisanal fleet operating off the south-western Iberian Peninsula. During 2004 and 2005 a study was undertaken aiming to provide a scientific basis for management. Data collection included information on aspects of the fishery, spawning season, size at first maturity, tangle and gill-net selectivity. Seven nominal mesh sizes were used (40, 45 and 50 mm tangle nets and 40, 50, 60 and 70 mm gill-nets). Spawning lasts from December to June, with peaks in March and May. Length at first maturity for females was estimated at 18.5 cm. Catch rates decreased sharply with increasing mesh size, with tangle nets providing the highest yields. The log-normal selectivity model provided the best fit for specimens that were wedged. The higher catch-per-unit-effort of the smaller mesh sizes and the modal length of the fitted selectivity curve being below the size-at-maturity for wedge sole, suggests that the 50 mm nominal mesh size tangle net is the most appropriate for ensuring the fishery sustainability. Nevertheless, the minimum legal size should increase to at least 18 cm and a time–area closure should be implemented off the Guadiana River mouth.

scholarly journals Fish Community Assemblages of Mining-Impacted Freshwaters at Prestea, Ghana

2018 ◽  
pp. 1-9
Author(s):  
Osei O. Antobre ◽  
Nat Owusu-Prempeh ◽  
Michael J. Twumasi-Ankrah
Keyword(s):  
Fish Community ◽  
Average Length ◽  
Mesh Size ◽  
Fish Diversity ◽  
Freshwater Ecosystem ◽  
Fish Community Structure ◽  
Average Width ◽  
H Index ◽  
Community Assemblage ◽  
Fish Samples

The study evaluated the fish community assemblage in the sections of the Subri river, the Ankobra river, and the “galamsey” pond within the Prestea community as impacted by alluvial mining activities. Gill nets of length 10 m and mesh size 1.27 cm were used to trap fish of average length 25.25 cm whilst cane baskets were used to trap fish of average width 10.40 cm using the catch and recapture method. All the 46 fish samples identified belong to 10 genera and 5 families. The Chichlidae was the dominant family, accounting for 60% of the total families observed. With an H’ index of 1.57 the Subri river had the most fish diversity in comparison with the Ankobra river and the “galamsey” pond, which had 1.21 and 0.71, respectively. Similarly, the Subri river had a more complex fish community structure than the Ankobra and “galamsey” pond. The dominant species, Oreochromis niloticus, has not yet been evaluated by the IUCN, but the least dominated Brienomyrus brachyistus could be regarded as “least concern”. Notwithstanding, these fish are essential for food by the local communities. There is a possibility that the alluvial mining might have influenced the complexities of fish species communities. Thus conservation efforts must be promoted to sustain fish communities and overall freshwater ecosystem health.

scholarly journals Community structure and niche breadth of some fish in Pangelang Protected Lake, Kapuas Hulu District

2021 ◽  
Vol 21 (2) ◽  
pp. 105-115
Author(s):  
Sri Endah Purnamaningtyas ◽  
Dimas Angga Hedianto ◽  
Nurfiarini Nurfiarini
Keyword(s):  
Community Structure ◽  
Fish Community ◽  
Niche Breadth ◽  
Fish Communities ◽  
Food Preferences ◽  
Survey Method ◽  
Fish Community Structure ◽  
Regional Patterns ◽  
Weather Changes ◽  
Detritivorous Fish

Ecologically, weather changes cause local deviations from regional patterns in waters. So that there will be changes in fish types and food habits.The purpose of this study was to determine changes in fish community structure, food preferences, and area of niches for each type of fish in Pangelang Protected Lake. The research was conducted using a survey method in October 2016 (low tide), June 2018 (transition) and September (flood) 2018. The results obtained: 1. Fish communities in Lake Pangelang obtained a total of 12 families, 30 genera, and 37 species. In the low tide season, there are 21 species of fish caught, 17 species of transition season and 16 types of flood during low tide. 2. In the low tide season, the fish community in Pangelang Lake is dominated by detritivorous fish. In the transitional season, the fish community in Pangelang Lake experiences changes with an increase in the union of phytoplanktivore and insectivore fish. During the flood season, the fish communities in Lake Pangelang underwent a change again where the union of herbivores that used plants increased.

scholarly journals Moulding the ideal crab: implications of phenotypic plasticity for crustacean stock enhancement

2020 ◽  
Author(s):  
Benjamin J Daly ◽  
Ginny L Eckert ◽  
W Christopher Long
Keyword(s):  
Phenotypic Plasticity ◽  
Large Scale ◽  
Field Studies ◽  
Stock Enhancement ◽  
Adaptive Responses ◽  
Ecological Performance ◽  
Significant Research ◽  
Morphological Differences ◽  
Plastic Responses

Abstract Numerous examples of behavioural and morphological differences between hatchery-cultured and wild individuals exist for a range of crustacean species; however, we submit that these variances are not deficiencies, but rather are adaptive responses to an unnatural rearing environment that may be detrimental in the natural environment. This phenotypic plasticity could be beneficial for stock enhancement because such plasticity suggests potential for change with adjustments to rearing protocols to achieve improved ecological competence. We examine how specific plastic responses can affect crustacean ecology through effects on predation, foraging, competition, and reproduction. For developing stock enhancement programmes, we recommend consideration of plastic phenotypic patterns before large-scale releases are initiated. Researchers can identify environmental factors that cue plasticity during hatchery rearing, determine if induced responses are ecologically influential after release into the wild, and examine the temporal scale on which phenotypic plasticity operates. Communal hatchery rearing at low-to-medium stocking densities with predator cues and natural substrates along with in situ conditioning, releases during periods of low predation risk, and coupled laboratory-field studies can contribute to improved ecological performance during stock enhancement. Finally, presentation of non-significant research results is needed to avoid bias towards hatchery–wild differences and help guide future conditioning programmes.

scholarly journals Determining Microbial Niche Breadth in the Environment for Better Ecosystem Fate Predictions

mSystems ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Emilie E. L. Muller
Keyword(s):  
Microbial Community ◽  
Global Change ◽  
Niche Breadth ◽  
Microbial Populations ◽  
Ecosystem Stability ◽  
Great Opportunity ◽  
Metagenomics Data ◽  
Integrated Omics ◽  
Current Context

ABSTRACT Integrated omics applied to microbial communities offers a great opportunity to analyze the niche breadths (i.e., resource and condition ranges usable by a species) of constituent populations, ranging from generalists, with a broad niche breadth, to specialists, with a narrow one. In this context, extracellular metabolomics measurements describe resource spaces available to microbial populations; dedicated analyses of metagenomics data serve to describe the fundamental niches of constituent populations, and functional meta-omics becomes a proxy to characterize the realized niches of populations and their variations though time or space. Thus, the combination of environmental omics and its thorough interpretation allows us to directly describe niche breadths of constituent populations of a microbial community, precisely and in situ. This will greatly facilitate studies of the causes influencing ecosystem stability, resistance, and resilience, as well as generation of the necessary knowledge to model and predict the fate of any ecosystem in the current context of global change.

Fish predators of the western rock lobster (Panulirus cygnus George) in a nearshore nursery habitat

1988 ◽  
Vol 39 (3) ◽  
pp. 307 ◽  
Author(s):  
RK Howard
Keyword(s):  
Fish Species ◽  
Fish Community ◽  
Carapace Length ◽  
Nursery Habitat ◽  
Rock Lobster ◽  
Lack Of Information ◽  
Gill Net ◽  
Fish Predators ◽  
Panulirus Cygnus ◽  
A Current

Nearshore limestone reefs of Western Australia represent an important nursery habitat for juveniles of the western rock lobster (Panulirus cygnus). As part of a trophic study of the fish community associated with these reefs, fishes were examined for evidence of predation on western rock lobsters. Six fish species were found to have ingested P. cygnus. Of these, Psammaperca waigiensis (sand bass), Pelsartia humeralis (sea trumpeter), Pseudolabris parilis (brown-spotted wrasse) and Plectorhyncus flavornaculatus (gold-spotted sweetlips) were among the ten most abundant fish in gill-net collections from the study site. P. cygnus formed a significant portion of the diet of P. waigiensis, but was < 5% of the dietary volume of other species. Predation occurred at all times of the day and was concentrated on small, newly-settled P. cygnus (8-15 mm carapace length). The vulnerability of lobsters to predation appears to be strongly related to size, and the cryptic habits that are unique to newly-settled stages can be explained in terms of the risks of predation. Assessment of the proportion of mortality of P. cygnus due to predation is hampered by a current lack of information on the natural densities of both fishes and small rock lobsters. However, conservative estimates indicate that an annual removal by fish of thousands of lobsters per hectare is likely, suggesting that predation is a major factor affecting the survival of P. cygnus on nursery reefs.

scholarly journals Kajian Kelimpahan Mikroplastik di Biota Perairan

2021 ◽  
Vol 19 (3) ◽  
pp. 638-648
Author(s):  
Saptian Wisnu Sandra ◽  
Arlini Dyah Radityaningrum
Keyword(s):  
Fish Species ◽  
Oreochromis Niloticus ◽  
Sea Water ◽  
Mesh Size ◽  
The Body ◽  
Aquatic Biota ◽  
Biological Processes ◽  
Whatman Filter Paper ◽  
Saccostrea Cucullata ◽  
Zeus Faber

Sampah plastik dapat terdegradasi menjadi mikroplastik (MP) dan nanoplastik (NP) melalui proses fisik, kimia, dan biologis. MP didefinisikan sebagai partikel plastik kecil berukuran < 5 mm. MP saat ini telah ditemukan di tubuh biota perairan, baik perairan permukaan maupun perairan laut. Tujuan penelitian ini adalah mengkaji MP pada biota perairan. Metode yang digunakan dalam penelitian ini adalah studi literatur terhadap artikel publikasi 10 tahun terakhir. Kajian dilakukan terhadap kelimpahan, ukuran, bentuk, warna, dan komposisi MP pada biota perairan permukaan dan laut. Review dilakukan terhadap penelitian di Indonesia dan berbagai wilayah di negara lain. Beberapa metode pengambilan sampel biota perairan yang digunakan dalam penelitian terdahulu yaitu menggunakan trawl atau pukat dasar (jaring polietilen), jaring pukat pantai (10 m x 1,5 m; ukuran mata jaring: 8 mm). Identifikasi MP pada saluran pencernakan biota ikan dilakukan menggunakan larutan KOH 10% selama 24 jam pada suhu 60°C, selanjutnya dilakukan penyaringan dengan kertas saring Whatman. Selanjutnya, proses identifikasi menggunakan mikroskop okuler dan FTIR untuk menentukan ukuran, bentuk, dan jenis polimer. Hasil kajian menunjukkan bahwa kelimpahan MP terbanyak pada biota perairan masing-masing yaitu 468 partikel MP/individu pada spesies Ikan Sapu-Sapu (Hypostomus plecostomus) di perairan sungai; 18 partikel MP/individu pada Ikan Nila Hitam (Oreochromis niloticus) di perairan payau; 1,4 – 7 partikel MP/individu pada spesies Tiram (Saccostrea cucullata) di perairan muara; 22,21 ± 1,7 partikel MP/individu pada spesies Ikan Thryssa kammalensis di perairan teluk; 2,7 ± 0,10 partikel MP/individu pada spesies Ikan Zeus faber di perairan selat; dan 22,3 partikel MP/individu pada Diadema sp. (Bulu babi) di perairan laut. MP yang dominan pada biota perairan adalah berukuran 20 μm – 50 μm, berbentuk fiber, dan berwarna hitam. Polyethylene (PE) ditemukan dominan pada biota perairan permukaan, serta polyprophylene (PP) dan polyethylene (PE) pada biota perairan laut.ABSTRACTPlastic wastes could be degraded into microplastic (MP) and nanoplastic (NP) through physical, chemical, and biological processes. MP was defined as the small particle of plastic with the size of < 5 mm. Currently, MP has been found in the body of aquatic biota both in the surface and sea water biota. This research aimed to investigate the microplastic content in aquatic biota. The study was conducted through literature review of the last 10 year published articles. The previous studies were reviewed in terms of abundance, size, shape, colour, and polymer type of MP in the aquatic biota in Indonesia and areas of other countries. Sampling of aquatic biota in the previous studies was conducted in several methods using trawling or bottom trawl (polyethylene net), beach trawl net (10 m x 1.5 m; mesh size: 8 mm). Identification of MP in the digestive tract of fish was conducted using 10% KOH solution for 24 hours at a temperature of 60°C, then was filtered using Whatman filter paper. Next, the identification process used an ocular microscope and FTIR to determine the polymer. The result demonstrated that the highest number of MP abundance was 468 MP particles/individual in the cattle fish (Hypostomus plecostomus) species in the river water; 18 MP particles/individual in the black nile fish (Oreochromis niloticus) species in the brackish water; 1.4 – 7 MP particles/individual in the oyster (Saccostrea cucullata) species in the estuary water; 22.21 ± 1.7 MP particles/individual in the Thryssa kammalensis fish species in the gulf water; 2.7 ± 0.10 MP particles/individual in the Zeus faber fish species in the strait water; and 22.3 MP particles/individual in the Diadema sp. (sea urchin) in the sea water. The most dominant MP size, shape, and colour in the aquatic biota was 20 μm – 50 μm, fiber, and black. Polyethylene (PE) was dominant in the surface water biota, whereas, polyprophylene (PP) and polyethylene (PE) in the sea water biota.

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