scholarly journals Biological studies on the commercial juvenile fish of the eastern coast of Libya.

2018 ◽  
Author(s):  
Salma Husaien ◽  
Mohammed El.Mor. ◽  
Keyword(s):  
Food Habits ◽  
Juvenile Fish ◽  
Correlation Coefficients ◽  
Size Composition ◽  
Common Species ◽  
Eastern Coast ◽  
Feeding Intensity ◽  
Commercial Fish ◽  
Biological Studies ◽  
Feeding Activities

The structures of juvenile commercial fish in the shallow water of eastern coast of Libya, Mediterranean Sea were investigated. Size composition, fish abundance, length frequency distribution, length-weight relationships, condition factors and food habits of the most common species were studied. Lithognathus mormyrus juvenile dominated the catch from February till December and the recruitment appeared in February, November, and December. Liza carinata and Diplodus annularis appeared from April until November and the recruitment showed in April, Liza ramada was recorded from April till August and recruitment were in April. Salpa sarpa appeared from March till November and recruitment appeared from March till June, Lichia amia appeared from April till December and recruitment appeared in June. All the species illustrated significant Length-weight relationships with high correlation coefficients indicating isometric growth.The condition factors of Lithognathus mormyrus, Liza ramada, Lichia amia were similar, increasing as the size increased. The monthly variation in conditions was influenced by feeding activities. The highest values of condition factors appeared in autumn for all the species reached the maximum values by the end of spring except Liza ramada where the highest values were shown at the end of summer. The feeding intensity was higher and food habits were varied.

scholarly journals Biological studies on the commercial juvenile fish of the eastern coast of Libya.

2018 ◽  
Author(s):  
Salma Husaien ◽  
Mohammed El.Mor. ◽  
Keyword(s):  
Food Habits ◽  
Juvenile Fish ◽  
Correlation Coefficients ◽  
Size Composition ◽  
Common Species ◽  
Eastern Coast ◽  
Feeding Intensity ◽  
Commercial Fish ◽  
Biological Studies ◽  
Feeding Activities

The structures of juvenile commercial fish in the shallow water of eastern coast of Libya, Mediterranean Sea were investigated. Size composition, fish abundance, length frequency distribution, length-weight relationships, condition factors and food habits of the most common species were studied. Lithognathus mormyrus juvenile dominated the catch from February till December and the recruitment appeared in February, November, and December. Liza carinata and Diplodus annularis appeared from April until November and the recruitment showed in April, Liza ramada was recorded from April till August and recruitment were in April. Salpa sarpa appeared from March till November and recruitment appeared from March till June, Lichia amia appeared from April till December and recruitment appeared in June. All the species illustrated significant Length-weight relationships with high correlation coefficients indicating isometric growth.The condition factors of Lithognathus mormyrus, Liza ramada, Lichia amia were similar, increasing as the size increased. The monthly variation in conditions was influenced by feeding activities. The highest values of condition factors appeared in autumn for all the species reached the maximum values by the end of spring except Liza ramada where the highest values were shown at the end of summer. The feeding intensity was higher and food habits were varied.

Distribution of seagrasses, and their fish and penaeid prawn communities, in Cairns harbour, a tropical estuary, Northern Queensland, Australia

1993 ◽  
Vol 44 (1) ◽  
pp. 193 ◽  
Author(s):  
RG Coles ◽  
WJ Lee Long ◽  
RA Watson ◽  
KJ Derbyshire
Keyword(s):  
Fish Species ◽  
Juvenile Fish ◽  
Dry Weight ◽  
Common Species ◽  
Shoot Density ◽  
Seagrass Beds ◽  
Commercial Fish ◽  
North Eastern ◽  
Commercial Species ◽  
Zostera Capricorni

From aerial photography (July 1987) and diving surveys (February 1988), 876 ha of seagrasses (eight species) were mapped in Cairns Harbour, tropical north-eastern Queensland. Zostera capricorni was the most common seagrass species and had the greatest biomass at 79 g m-2 dry weight of stems and leaves and 180 g m-2 dry weight of roots and rhizomes. The maximum shoot density found was 4798 shoots m-2 of Halodule pinifolia, the second most common species. Seagrasses were found only between 0.5 and 5.0 m below mean sea level. Zostera capricorni was found at the shallowest depths, Halodule pinifolia at the deepest depths. Twenty species of penaeid prawns, nine of which are marketed commercially, were sampled from the seagrass beds. Abundances of prawns of commercial species were significantly greater on seagrass-covered substrata than on nonvegetated substrata. Overall, 5614 mostly small or juvenile fish, representing 134 taxa, were sampled from seagrasses in Cairns Harbour. The most numerous fish species were a goby, Yongeichthys criniger, and a pony fish, Leiognathus splendens. Only 15 species were highly valued as recreational fish, and only 11 species were highly valued as commercial fish. Of the fish species, five (4%) were highly valued species of both groups. The density of fish on the seagrass beds was estimated to be 8809 fish ha-1.

Dependence of efficiency of natural fish reproduction in water bodies of Kazakhstan from water level

2021 ◽  
pp. 32-41
Author(s):  
K.B. Isbekov ◽  
E.V. Kulikov ◽  
S.Zh. Asylbekova
Keyword(s):  
Water Content ◽  
Water Regime ◽  
Juvenile Fish ◽  
Hydrological Regime ◽  
Water Bodies ◽  
Fish Reproduction ◽  
Data Set ◽  
Commercial Fish ◽  
Level Of Significance ◽  
The Impact

The article deals with the relationship between the hydrological regime of water bodies and the efficiency of fish reproduction. The hydrological regime of water bodies in years of different water content influences the reproduction and, accordingly, the quantitative and qualitative composition of ichthyocenoses. The easiest way to assess the efficiency of fish reproduction is by such an indicator as the productivity of juveniles, i.e. the number of juvenile fish per unit area or volume. The material for this work was carried out in large fishing reservoirs of the Republic of Kazakhstan in the process of fishery research (2013–2018). Comparison of hydrological parameters and productivity of juveniles by years shows their relationship. Correlation coefficient between water content (runoff) of the river Zhaiyk and juvenile yield +0.73 (data set for 11 years, reliable for the level of significance p = 0.01). The yield of juvenile fish from Lake Balkhash has a high correlative dependence on the inflow of water into the lake (r = +0.826) (massif 2013–2018, reliable for the level of significance p = 0.05). Correlation analysis showed that the productivity of juvenile fish in the Kapshagai reservoir has an average degree of dependence on water content (average annual level) (r = +0.641, reliable for the level of significance p = 0.05). Regular relationships between the water regime and the efficiency of reproduction (productivity of juveniles) of fish have been established. The efficiency of natural reproduction of commercial fish species in modern conditions of the water regime, water withdrawal for economic needs and the impact of fishing is significantly reduced, but with the implementation of the reclamation measures proposed in the work, its partial restoration is possible.

scholarly journals DNA barcode identification of commercial fish sold in Mexican markets

Genome ◽  
2018 ◽  
Vol 61 (6) ◽  
pp. 457-466 ◽  
Author(s):  
Stephanie Sarmiento-Camacho ◽  
Martha Valdez-Moreno
Keyword(s):  
Conservation Status ◽  
Dna Barcode ◽  
Common Species ◽  
Morphological Identification ◽  
Dna Barcodes ◽  
Commercial Fish ◽  
Sphyrna Lewini ◽  
Pangasianodon Hypophthalmus ◽  
Makaira Nigricans ◽  
The Status

The substitution of high-value fish species for those of lower value is common practice. Although numerous studies have addressed this issue, few have been conducted in Mexico. In this study, we sought to identify fresh fillets of fish, sharks, and rays using DNA barcodes. We analyzed material from “La Viga” in Mexico City, and other markets located on the Gulf and Caribbean coasts of Mexico. From 134 samples, we obtained sequences from 129, identified to 9 orders, 28 families, 38 genera, and 44 species. The most common species were Seriola dumerili, Pangasianodon hypophthalmus, Carcharhinus falciformis, Carcharhinus brevipinna, and Hypanus americanus. Pangasianodon hypophthalmus was most commonly used as a substitute for higher-value species. The substitution rate was 18% of the total. A review of the conservation status of the specimens identified against the IUNC list enabled us to establish that some species marketed in Mexico are threatened: Makaira nigricans, Lachnolaimus maximus, Hyporthodus flavolimbatus, and Isurus oxyrinchus are classified as vulnerable; Lopholatilus chamaeleonticeps and Sphyrna lewini are endangered; and the status of Hyporthodus nigritus is critical. These results will demonstrate to the Mexican authorities that DNA barcoding is a reliable tool for species identification, even when morphological identification is difficult or impossible.

scholarly journals Seasonal Occurence of Food and Feeding Habit of Labeo bata(Hamilton) (Cypriniformes : Cyprinidae)

2015 ◽  
Vol 12 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Md. Abdur Razzaq Joadder
Keyword(s):  
Food Habits ◽  
Feeding Habits ◽  
Feeding Habit ◽  
Water Bodies ◽  
Feeding Intensity ◽  
Higher Plant ◽  
Plant Parts ◽  
Labeo Bata ◽  
Food And Feeding ◽  
Potential Food

Food and feeding habits of fishes have a great significance in aquaculture practices. It helps to select such species of fishes for culture which will utilize all the available potential food of the water bodies without much competition with one another but will live in association with other fishes. This paper deals with the feeding intensity and food habits of L. bata . Food and feeding habit of freshwater minor carp Labeo bata (120 to 250 mm total length) were studied. The fish is a herbivore, feeding mainly on algae (22.32 %), higher plant parts (31.26 %), protozoans (7.42 %), crustaceans (15.33 %), insects (3.56 %), muds, sand, debris and detritus (16.32 %) and unidentified food materials (3.99%).Journal of Science Foundation, 2014;12(1):7-15

Mercury levels in six species of Australian commercial fish

1980 ◽  
Vol 31 (4) ◽  
pp. 469 ◽  
Author(s):  
R Chvojka ◽  
RJ Williams
Keyword(s):  
Total Mercury ◽  
Size Range ◽  
Graphical Method ◽  
Correlation Coefficients ◽  
Mercury Content ◽  
Fish Length ◽  
Commercial Fish ◽  
The Relationship ◽  
Commercial Size ◽  
Zeus Faber

The total mercury content of six species of Australian commercial fish (John dory. Zeus faber: mirror dory. Zenopsis nebulosus; tiger flathead, Neoplatycephalus richardsoni; rubberlip morwong, Nemadactylus douglasii; jackass morwong, Nemadactylus macroprerus; and sand whiting, Sillago ciliata) is reported. Total mercury content is regressed against fish length and the resultant equations and correlation coefficients are presented for each species. A length-frequency histogram derived from the Sydney Fish Market data and a length-mercury content curve are plotted as an overlay for each of the six species. The integrated average mercury content (mg/kg) has been calculated for each species and these are as follows: sand whiting, 0.08; rubberlip morwong, 0.13; tiger flathead, 0.14; John dory, 0.14; mirror dory, 0.15; and jackass morwong, 0.16. The graphical method adequately demonstrates the relationship between mercury levels and the commercial size range of particular species.

Iospilids (Polychaeta: Iospilidae) from the northwest Caribbean Sea, with observations on reproductive structures

Zootaxa ◽  
2006 ◽  
Vol 1211 (1) ◽  
pp. 53 ◽  
Author(s):  
SOLEDAD JIMÉNEZ-CUETO ◽  
EDUARDO SUÁREZ-MORALES ◽  
SERGIO I. SALAZAR-VALLEJO
Keyword(s):  
Caribbean Sea ◽  
Common Species ◽  
Eastern Coast ◽  
Reproductive Process ◽  
Morphological Variations ◽  
Reproductive Structures ◽  
Morphological Adaptations ◽  
The Family ◽  
Mode Of Life ◽  
The Caribbean

Iospilids are a small, inconspicuous group of holopelagic polychaetes that dwell in the upper layers of tropical, temperate, and cold waters of the world. Representatives of this interesting and infrequent group were collected during four oceanographic cruises off the eastern coast of the Yucatan Peninsula, northwest Caribbean Sea. Three of the four species currently known in the family were recorded: Iospilus phalacroides Viguier, 1886, Phalacrophorus pictus Greeff, 1879, and P. uniformis Reibisch, 1895. The latter was the most common species in the area; it occurred during the four cruises and represented more than 92% of the total iospilid specimens caught; it was slightly more abundant in nighttime samples. New observations of reproduction-related morphological variations and sexual dimorphism are presented for P. uniformis. These may be regarded as morphological adaptations to the planktic mode of life thus favouring the efficiency of the reproductive process in the water column. These are the first records of the family Iospilidae in the Caribbean Basin. Revised generic and species diagnoses, taxonomic illustrations and notes, and an identification key are given here for the species recorded in the Caribbean.

The herpetofauna of Kioloa, New South Wales: baseline observational data collected 30 years ago and inspired by R. E. Barwick

2014 ◽  
Vol 62 (1) ◽  
pp. 100 ◽  
Author(s):  
Klaus Henle ◽  
Will Osborne ◽  
Frank Lemckert
Keyword(s):  
New South ◽  
New South Wales ◽  
Common Species ◽  
Current Data ◽  
Eastern Coast ◽  
Field Station ◽  
South Wales ◽  
Anthropogenic Habitat ◽  
Reptile Species ◽  
Frog Species

There is increasing concern about the global decline of amphibians and reptiles. One problem with documenting declines and identifying underlying causes is the absence of historical data to compare to current data. Here we provide historic data for Kioloa on the south-eastern coast of New South Wales. In this region considerable clearing of natural forest and woodland and creation of farmland ponds took place during the second half of the 20th century. The Australian National University has a field station at Kioloa and R.E. Barwick introduced us to the field station and what was known of the herpetofauna in the mid-1980s. We undertook detailed observational surveys of the herpetofauna at this time and we revisited the area at other times, focusing on the coastal habitats. We found 13 species of frogs and 11 species of reptiles. Three further frog species and one reptile species known to occur in the area in the 1980s were not detected by us. More recently, one further frog species and six reptile species were added to the list, raising the total to 17 frog and 18 reptile species. The number and composition was similar to other locations of coastal New South Wales, except for some of the rarely encountered species. No strictly forest-dependent species were observed in the partially cleared survey area and such species presumably had already disappeared from these areas already before we commenced our observations. The frog Pseudophryne bibronii was still common in tall open-forest but was uncommon in partially cleared areas. Six species of frogs and one species of reptile presumably benefited from the anthropogenic habitat modifications. No declines of common species of reptiles occurred between the mid-1980s and 1993 but all species of frogs were very rare in 1993 due to very dry conditions. Litoria aurea, a threatened species of frog that was widespread in the mid-1980s, survives (2012) only at one site in the area.

Evaluation of Reproduction Conditions of Commercial Fish in Iriklin Reservoir to the Juvenile Fish Productivity

2015 ◽  
Vol 15 (2) ◽  
pp. 72-75
Author(s):  
Vladimir Pavlovich Ermolin ◽  
◽  
Ilia Aleksandrovich Belianin ◽  
Dmitri Yurievich Tiulin ◽  
◽  
...  
Keyword(s):  
Juvenile Fish ◽  
Commercial Fish ◽  
Fish Productivity

Food habits and dietary overlap of perlid stoneflies (Plecoptera) in a tributary of Lake Ontario

1981 ◽  
Vol 59 (10) ◽  
pp. 2030-2037 ◽  
Author(s):  
James H. Johnson
Keyword(s):  
New York ◽  
Food Consumption ◽  
Food Habits ◽  
Diet Composition ◽  
Lake Ontario ◽  
Food Habit ◽  
Dietary Overlap ◽  
Feeding Intensity ◽  
Similar Formula

Food habit studies were conducted on the nymphs of three species of sympatric perlid stoneflies from May to September 1979 in Orwell Brook, New York. A total of 1106 specimens were examined, which included 744 Phasganophora capitata, 251 Paragnetina immarginata, and 111 Acroneuria abnormis. Chironomids, trichopterans, and ephemeropterans were generally the principal, prey of all three species. Using Horn's measure of overlap, the monthly diets of P. immarginata and P. capitata were most similar [Formula: see text] and the diets of A. abnormis and P. immarginata[Formula: see text] least similar. Diel trends in food consumption during July indicated that the feeding intensity of both P. immarginata and P. capitata was the greatest from 2100 to 0500 hours. Examination of the guts of P. immarginata and P. capitata at 4-h intervals over a 24-h period showed that there was considerable variation in the diel diet composition of these species.

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