Orientation of Mediterranean fish larvae varies with location

This work develops a new method, the box-balance model (BBM), to assess the role of hydrodynamic structures in the survival of fish larvae. The BBM was applied in the northwest Mediterranean to field data, on 2 small pelagic fish species whose larvae coexist in summer: Engraulis encrasicolus, a dominant species, and Sardinella aurita, which is expanding northwards in relation to sea warming. The BBM allows one to quantify the contribution of circulation, with significant mesoscale activity, to the survival of fish larvae, clearly separating the effect of transport from biological factors. It is based on comparing the larval abundances at age found in local target areas, associated with the mesoscale structures (boxes), to those predicted by the overall mortality rate of the population in the region. The application of the BBM reveals that dispersion/retention by hydrodynamic structures favours the survival of E. encrasicolus larvae. In addition, since larval growth and mortality rates of the species are required parameters for application of the BBM, we present their estimates for S. aurita in the region for the first time. Although growth and mortality rates found for S. aurita are both higher than for E. encrasicolus, their combined effect confers a lower survival to S. aurita larvae. Thus, although the warming trend in the region would contribute to the expansion of the fast-growing species S. aurita, we can confirm that E. encrasicolus is well established, with a better adapted survival strategy.

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DIVERSITY OF FISH LARVAE AROUND THE ESTUARY OF THE BANYUASIN RIVER, SOUTH SUMATERA PROVINCE

BIOVALENTIA Biological Research Journal ◽

10.24233/biov.6.2.2020.181 ◽

2020 ◽

Vol 6 (2) ◽

Author(s):

Moh. Rasyid Ridho ◽

Enggar Patriono ◽

Sarno Sarno ◽

Sahira Wirda

Keyword(s):

Initial Phase ◽

Sampling Method ◽

Environmental Changes ◽

Negative Impact ◽

Fish Larvae ◽

River Estuary ◽

Sampling Technique ◽

Critical Phase ◽

Morisita Index ◽

Index Value

The initial phase of the fish life cycle is a critical phase associated with high mortality due to sensitivity to predators, food availability, and also environmental changes that occur in nature. Disruption of the initial stages of fish life has a negative impact on fish populations. Until now there has been no information about fish larvae around the Banyuasin River Estuary. Therefore, research is needed on the diversity of fish larvae around the Banyuasin River Estuary, South Sumatra Province. This research were used purposive sampling method, sampling technique in the form of Cruise Track Design with continuous parallel survey trajectory. Based on the results of the study found as many as 10 families consisting of 1483 individuals of fish larvae in March and 1013 individuals of fish larvae in May consisting of Engraulidae 1,601 individuals of fish larvae, Mungiloidei as many as 109 individuals, Leiognathidae 50 individuals, Chanidae 453 individuals, Scatophagidae 20 individuals , Belonidae 39 individuals, Gobioididae 5 individuals, Chandidae 183 individuals, Syngnatihidae 6 individuals, and Gobiidae 30 individuals fish larvae. The index value of fish larvae diversity is classified as medium category (March 1.02 and May 1.12), Morisita index shows the distribution pattern of fish larvae classified as a group (March 0-14.17 and May 2.43-10.40 ), and the evenness index value is in the medium category (March 0.437 and May 0.521).

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Faculty Opinions recommendation of Tracking signals of change in Mediterranean fish diversity based on local ecological knowledge.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13308956.14672054 ◽

2011 ◽

Author(s):

Joachim Claudet ◽

Antonio Di Franco

Keyword(s):

Local Ecological Knowledge ◽

Fish Diversity ◽

Ecological Knowledge ◽

Mediterranean Fish

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Pengaruh ovaprim, aromatase inhibitor, dan hipofisa terhadap kualitas telur ikan Lele Dumbo (Clarias gariepinus)

e-Journal BUDIDAYA PERAIRAN ◽

10.35800/bdp.5.1.2017.14836 ◽

2017 ◽

Vol 5 (1) ◽

Author(s):

Erwin A. Aziz ◽

Ockstan Kalesaran

Keyword(s):

Survival Rate ◽

Experimental Design ◽

Aromatase Inhibitor ◽

Fish Larvae ◽

Clarias Gariepinus ◽

Randomized Design ◽

Completely Randomized Design ◽

The Difference ◽

Hatching Eggs

This study aimed to determine the effect of ovaprim hormone, aromatase inhibitor and pituitary on the quality of the catfish eggs (Clarias gariepinus). Experimental Design used was Completely Randomized Design (CRD) with four treatments, each with three replications. Treatment A: ovaprim; treatment B: Aromatase inhibitors, treatment C: hypophysis and treatment D: Control. The results showed that the difference in treatment gave highly significant effect on fertilization and hatching eggs but no significant effect on the survival rate of larvae. Aromatase inhibitor hormone was the best because it provided highly significant effect on fertilization (92.66%), hatchability of eggs (95%), and surviva rate (81.33%) of fish larvae. Keywords : Clarias gariepinus. Ovaprim, Aromatase Inhibitor, Hypophysis, egg, larvae

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Isolation, morphometry, and culture of Colurella sp. (Rotifera: Ploimida)

AQUATIC SCIENCE & MANAGEMENT ◽

10.35800/jasm.1.2.2013.7276 ◽

2013 ◽

Vol 1 (2) ◽

pp. 143

Author(s):

Petrus P Letsoin ◽

Henneke Pangkey ◽

Julius Sampekalo ◽

Inneke F.M Rumengan ◽

Stenly Wullur ◽

...

Keyword(s):

Body Size ◽

Marine Fish ◽

Fish Larvae ◽

Nannochloropsis Oculata ◽

Tropical Fish ◽

Sampling Location ◽

Larval Rearing ◽

Brachionus Rotundiformis ◽

Marine Fish Larvae ◽

Significant Difference

The rotifer Brachionus rotundiformis (total body length 240.59±10.24 μm, lorica length 175.28±9.18 μm, and lorica width 124.28±7.76μm) is commonly used as starter food in the larval rearing of marine fish. But, larvae of some marine tropical fish species required starter food with body size smaller than B. rotundiformis. The present study was aimed to isolate minute rotifers from nature and to assess the possibility of culturing these rotifers. Sampling of rotifers was conducted in an estuary of Mangket (Kema-Minut), using plankton net (mesh size 40 µm). A trial of culturing the rotifers was conducted at salinities of 10, 20 and 30 ppt by using a microalga, Nannochloropsis oculata. A species of rotifer identified as Colurella sp. (family Lepadellidae) was successfully isolated from the sampling location. Body size of Colurella sp. was extremely small (Total length 123.22±5.45 μm, lorica length 95.96±3.81 μm, and lorica width 53.57±3.11 μm), which were smaller than Brachionus rotundiformis SS-type as a conventional starter food for marine fish larvae. Results of culturing the minute rotifer Colurella sp. showed that the species grew well at salinities of 10, 20 and 30 ppt with no significant difference among treatments (ANOVA, p>0.05), indicating a potential use of minute rotifer Colurellasp. as starter food for marine fish larvae. Rotifera Branchionus rotundiformis (ukuran tubuh: panjang total 240,59±10,24 μm, panjang lorika 175,28±9,18 μm, dan lebar lorika 124,28±7,76μm) sering digunakan sebagai pakan awal pemeliharaan larva ikan laut. Namun, larva beberapa spesis ikan laut tropis membutuhkan pakan awal berukuran tubuh lebih kecil dari Branchionus rotundiformis. Penelitian ini bertujuan untuk mendapatkan minute rotifer dari alam (berukuran tubuh lebih kecil dari B. rotundiformis) dan menguji kemungkinan pemeliharaannya. Sampling rotifer dilakukan di perairan estuari Desa Mangket (Kema-Minut), menggunakan plankton net (ukuran mata jaring 40 µm). Uji coba pemeliharaan dilakukan pada salinitas (10, 20, dan 30 ppt) dengan menggunakan Nannochloropsis oculata. Satu spesies minute rotifer yang teridentifikasi sebagai Colurella sp. (family Lepadellidae) berhasil diisolasi dari lokasi sampling. Colurella sp. memiliki ukuran tubuh sangat kecil (panjang total [PT] 123,22±5,45 µm, panjang lorika [PL] 95,96±3,81 µm, dan lebar lorik [LL] 53,57±3,11 µm) yang mana lebih kecil dari Branchionus rotundiformis tipe-SS sebagai pakan awal larva ikan laut. Hasil uji coba pemeliharaan minute rotifer Colurella sp. menunjukkan bahwa spesis ini dapat tumbuh pada salinitas 10, 20, dan 30 ppt dengan perbedaan kepadatan populasi yang tidak signifikan antar perlakuan (Uji ANOVA, p > 0.05) mengindikasikan potensi pemanfaatan minute rotifer Colurella sp. sebagai pakan awal larva ikan laut.

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