Temperature-dependent larval survival and growth differences among populations of Murray cod (Maccullochella peelii)

2019 ◽  
Vol 70 (4) ◽  
pp. 459
Author(s):  
D. P. Svozil ◽  
R. K. Kopf ◽  
R. J. Watts ◽  
A.O. Nicholls

Different populations of organisms can vary widely in their responses to environmental conditions and this variation is fundamental to the persistence of species. Using a common garden experiment, we examined temperature-specific growth and survival responses of larvae among populations of Murray cod (Maccullochella peelii) from four regions of the Murray–Darling Basin (MDB), Australia. Fish larvae from the four regions differed significantly in their growth and survival responses at high water temperatures ≥26°C. At 30°C, survival rates of larvae by Day 20 ranged from 0% in the Lachlan region to 82% in the southern region. Opposite to the geographical differences in survival, growth of larvae was highest in the Lachlan (14.8–15.4-mm standard length 95% CI) and lowest in the southern region (13.4–13.9-mm standard length 95% CI) at 26°C where sufficient numbers survived for comparison. Geographical differences in growth and survival responses did not follow a consistent latitudinal gradient as observed for other species, but were closely linked with previously described genetic structure. Our results suggest that the upper thermal limit of M. peelii larvae is near common river temperatures in the MDB and that maintaining functional response diversity and underlying genetic diversity will be important for ensuring the resilience of this apex predator under future climate change.

2007 ◽  
Vol 3 (2) ◽  
pp. 19
Author(s):  
M. Nasir ◽  
K. Sumawidjaja ◽  
K. Sumawidjaja ◽  
Irzal Effendi

<p>Dua percobaan telah dilakukan, yaitu tanpa dan dengan larva ikan. Percobaan pertama, yang menggunakan 3 konsentrasi diazinon 0. 2 dan 4 ppm dan 3 ulangan, mempelajari pertumbuhan rotifera, cladocera dan copepoda. Percobaan kedua mempunyai 2 perlakuan, yaitu diazinon 0 dan 4 ppm (yang terbaik dari percobaan pertama) serta 4 ulangan untuk mengevaluasi: 1) ketersediaan, pemanfaatan dan susunan jasad-jasad pakan, 2) pertumbuhan dan kelangsungan hidup larva, serta 3) perkembangan larva ikan. Larva yang berumur satu hari ditebar pada saat kelimpahan rotifera tertinggi di hapa dengan kepadatan 40 larva/1 atau 3.200 larva/hapa. Hapa (mesh 0,8 mm) yang berukuran 50x40x50 cm ditempatkan dalam kolam-kolam beton yang berukuran 4,25x2,00x 0,65 m. Kolam-kolam ini mula-mula dikeringkan selama 2 hari, dipupuk dengan kotoran ayam 1.000 g/m3 dan diisi air setinggi 50 cm. Keesokan harinya kolam dipupuk dengan urea dan tripel superfosfat masing-masing 20 dan 30 g/m3. Dua hari kemudian air diberi diazinon sesuai perlakuan. Hasil percobaan pertama menunjukkan bahwa diazinon meningkatkan ketersediaan rotifera. Populasi rotifera tertinggi dicapai di kolam yang mendapat diazinon 4 ppm. Percobaan kedua memberikan laju pertumbuhan harian dan kelangsungan hidup larva ikan serta ketersediaan dan pemanfaatan rotifer tertinggi pada pemberian diazinon 4 ppm.</p> <p>Kata kunci: Pakan alami, larva. <em>Oxyeleotris marmorata, </em>diazinon. kelangsungan hidup, pertumbuhan</p> <p> </p> <p>ABSTRACT</p> <p>Two experiments were conducted, without and with fish larvae. The first experiment, utilizing 3 concentrations of diazinon, i.e. 0, 2 and 4 ppm and 3 replications, evaluated the growth of rotifers, cladocerans and copepods. The second experiment had 2 treatments, i.e. 0 and 4 ppm diazinon and 4 replications evaluated: 1) the availability, utilization and composition of food organisms, 2) the growth and survival rates offish larvae, and 3) the development of larvae. One-day old larvae were stocked at times of highest rotifer concentrations in hapas at 40 larvae/1 or 3,200 larvae/hapa. Hapas (0,8 mm mesh) of 50x40x50 cm were placed in concrete ponds of 4.25x2.00x0,65 m. The ponds were dried for 2 days, fertilized with chicken manure 1.000 g/m3 and filled with water up to 50 cm deep. Next day, the ponds were fertilized with urea and triple superphosphate 20 and 30 g/m3 respectively. Two days later, the water was treated with diazinon according to treatments. The results of the first experiment showed that diazinon increased the availability of rotifers. The highest rotifer populations were obtained in ponds receiving 4 ppm diazinon. The second experiment gave highest daily growth and survival rates of fish larvae, te availability and utilization of rotifers at 4 ppm diazinon.</p> Key words: Natural foods, larvae, <em>Oxyeleotris marmorata, </em>diazinon, survival, growth.


Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 505
Author(s):  
Luz Hurtado ◽  
Claudio D. Miranda ◽  
Rodrigo Rojas ◽  
Félix A. Godoy ◽  
Mark A. Añazco ◽  
...  

The culture of red cusk eel Genypterus chilensis is currently considered a priority for Chilean aquaculture but low larval survival rates have prompted the need for the continuous use of antibacterials. The main aim of this study was to evaluate the role of live feed as a source of antibacterial-resistant bacteria in a commercial culture of G. chilensis. Samples of rotifer and Artemia cultures used as live feed were collected during the larval growth period and culturable bacterial counts were performed using a spread plate method. Rotifer and Artemia cultures exhibited high levels of resistant bacteria (8.03 × 104 to 1.79 × 107 CFU/g and 1.47 × 106 to 3.50 × 108 CFU/g, respectively). Sixty-five florfenicol-resistant isolates were identified as Vibrio (81.5%) and Pseudoalteromonas (15.4%) using 16S rRNA gene sequence analysis. A high incidence of resistance to streptomycin (93.8%), oxytetracycline (89.2%), co-trimoxazole (84.6%), and kanamycin (73.8%) was exhibited by resistant isolates. A high proportion of isolates (76.9%) carried the florfenicol-resistance encoding genes floR and fexA, as well as plasmid DNA (75.0%). The high prevalence of multiresistant bacteria in live feed increases the incidence of the resistant microbiota in reared fish larvae, thus proper monitoring and management strategies for live feed cultures appear to be a priority for preventing future therapy failures in fish larval cultures.


1980 ◽  
Vol 37 (7) ◽  
pp. 1063-1069 ◽  
Author(s):  
Robert G. Werner ◽  
J. H. S. Blaxter

Growth and survival rates were determined for 4- to 12-wk-old herring larvae (Clupea harengus) reared at prey densities of 0.03, 0.1, 0.3, 1.0, and 3.0 Artemia nauplii/mL. The time required for food to pass through the gut in relation to prey density was also estimated.The results indicate that significant deleterious effects occur when larvae are reared at the two lowest prey densities. Survival was reduced at 0.03 Artemia/mL and growth was lowered at 0.03 and 0.1 Artemia/mL. Growth depensation leading to size hierarchies was not correlated with prey density. Food passed through the gut more rapidly at high prey densities. The threshold prey density above which changes in numbers of prey have little effect on survival or growth was estimated to lie between 0.1 and 0.3 Artemia/mL, possibly near 0.17 Artemia/mL.Key words: fish larvae, herring, feeding ecology, predator-prey


2019 ◽  
Vol 18 (2) ◽  
pp. 209-214
Author(s):  
Jojo Subagja ◽  
Vitas Atmadi Prakoso ◽  
Otong Zenal Arifin ◽  
Anang Hari Kristanto

Proper stocking density on larval rearing of barred loach (Nemacheilus fasciatus Valenciennes, 1846) is very important in terms of obtaining the best growth and survival rate. This study was aimed to observe the growth and survival rate of barred loach subjected to different larval stocking density. Fish larvae were obtained by artificial spawning from in aquarium. Larvae were stocked on aquariums (50 × 40 × 30 cm) with three stocking density treatments (5, 10, and 15 individuals/L) and three replications. The experimental fish larvae were fed by Artemia and commercial feed (crude protein content: 30%) and feeding frequency twice per day (ad libitum). The length and weight were reassured every 10 days during 70 days of rearing period. Temperature, pH, and dissolved oxygen were measured at each treatment. Data obtained from measurements were analysed to assess the length gain, weight gain, specific growth rate (SGR), biomass gain, and survival rate. The results showed length gain of 3.35 ± 0.01, 2.94 ± 0.10, and 2.82 ± 0.15 cm and weight gain of 0.573 ± 0.023, 0.436 ± 0.018, and 0.417 ± 0.043 g in larval stocking density of 5, 10 and 15 individuals/L, respectively. Specific growth rates and biomass growth were of 6.22 ± 0.41, 5.93 ± 0.21, and 5.68 ± 0.41 %/day and 94.04 ± 5.39, 146.80 ± 3.81, and 167.24 ± 17.48 g in larval stocking density of 5, 10 and 15 individuals/L, respectively. Meanwhile, the survival rates obtained in this study were 89.13 ± 7.25, 93.13 ± 5.13, and 76.50 ± 3.54 % in larval stocking density of 5, 10 and 15 individuals/L, respectively. Increased stocking density has a negative impact on the growth and survival rate of barred loach.


2002 ◽  
Vol 59 (12) ◽  
pp. 1858-1873 ◽  
Author(s):  
H.-H Hinrichsen ◽  
C Möllmann ◽  
R Voss ◽  
F W Köster ◽  
G Kornilovs

A coupled hydrodynamic–trophodynamic individual-based model of drift and feeding was utilized to analyze the intra- and inter-annual variability in growth and survival of cod (Gadus morhua) larvae in the central Baltic Sea. Highly temporally and spatially resolved simulated flow fields were used to investigate the potential drift of larval cod from the centre of spawning effort in the Bornholm Basin towards their nursery areas through temporally resolved three-dimensional idealized prey fields. Stomach content analyses of larval cod from the Bornholm Basin revealed calanoid copepod nauplii and early copepodite stages to be the preferred prey organisms. The results of the model runs indicate that larval cod changed from a nonlimited to a food-limited stage because of the strong decrease in abundance of the calanoid copepod Pseudocalanus elongatus during the last two decades. The modeling study revealed retention and dispersal from the main spawning ground to be a key process influencing larval survival. When P. elongatus was available in the prey fields, high cod larval survival rates occurred in spring and early summer. In contrast, when P. elongatus was not available, hatched larvae had only high survival probabilities later in the year or if they were transported into shallower coastal regions.


2020 ◽  
Vol 650 ◽  
pp. 289-308 ◽  
Author(s):  
V Raya ◽  
J Salat ◽  
A Sabatés

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Melinda Boyers ◽  
Francesca Parrini ◽  
Norman Owen-Smith ◽  
Barend F. N. Erasmus ◽  
Robyn S. Hetem

AbstractSouthern Africa is expected to experience increased frequency and intensity of droughts through climate change, which will adversely affect mammalian herbivores. Using bio-loggers, we tested the expectation that wildebeest (Connochaetes taurinus), a grazer with high water-dependence, would be more sensitive to drought conditions than the arid-adapted gemsbok (Oryx gazella gazella). The study, conducted in the Kalahari, encompassed two hot-dry seasons with similar ambient temperatures but differing rainfall patterns during the preceding wet season. In the drier year both ungulates selected similar cooler microclimates, but wildebeest travelled larger distances than gemsbok, presumably in search of water. Body temperatures in both species reached lower daily minimums and higher daily maximums in the drier season but daily fluctuations were wider in wildebeest than in gemsbok. Lower daily minimum body temperatures displayed by wildebeest suggest that wildebeest were under greater nutritional stress than gemsbok. Moving large distances when water is scarce may have compromised the energy balance of the water dependent wildebeest, a trade-off likely to be exacerbated with future climate change.


2020 ◽  
Vol 25 (3) ◽  
pp. 110-114
Author(s):  
Heppi Iromo ◽  
Dori Rachmawani ◽  
Abdul Jabarsyah ◽  
Zainuddin Zainuddin

The high demand for mud crabs in North Kalimantan causes catch to increase in the wild. If it is not balanced with efforts to increase its aquaculture of mud crab, in the future there will be a decline in population. This study aims to determine the growth and survival rate of mud crab seed (crablet, Scylla serrata) in the application method of different types of trash fish. This research used a completely randomized design with 4 treatments and 3 replications. The Crablet used carapace width average 0.07-0.09 cm and weigh average 0.05-0.07 g with total 150 crablets. The treatments applied by trash fish were (A) Tilapia Fish (Oreochromis mossambicus), (B) Longfin Herrings Fish (Ilisha elongata), (C) Sword Fish (Trichiurus lepturus) and (D) Snails (Telescopium telescopium). The results were The best weight growth of crablet occurs in the treatment of T. lepturus (P>0.05) and  the highest of survival rates of crablet were found in treatment T. telescopium (P<0.05)  than the other. The trash fish were used turned out to be able survival of crablet mud crab (Scylla serrata).


2019 ◽  
Vol 7 (2) ◽  
pp. 335
Author(s):  
Mikraim J. Kaseger ◽  
Henneke Pangkey ◽  
Diane J. Kusen ◽  
Henky Manoppo ◽  
Winda M. Mingkid ◽  
...  

The purpose of this study was to find out the survival rates of betta fish larvae (cupang) that were given life feed Alona sp., boiled egg yolk and commercial feed for 21 days. Data analysis was performed by one-way ANOVA, and continued with BNJ (Tukey) test. The result of the survival rate is as follow treatment with life feed Alona sp. 56%, treatment with boiled egg yolk 26%, and treatment with commercial feed 0%. The results of statistical tests show there are significant differences.  Significant value p <.0002 (<.05). Water quality parameter measured during the study was temperature of 26 ºC.Keywords: betta fish larvae, life feed, Alona sp., survival rateABSTRAKTujuan penelitian ini adalah untuk mendapatkan laju kelangsungan hidup larva ikan betta (cupang) yang dibeerikan pakan alami Alona sp., rebusan kuning telur dan pakan komersil selama 21 hari.  Analisis data dilakukan dengan ANOVA one way, dan dilanjutkan dengan uji BNJ (Tukey).  Hasil laju kelangsungan hidup adalah sebagai berikut, perlakuan dengan pakan alami Alona sp. 56%, perlakuan dengan rebusan kuning telur 26%, dan perlakuan dengan pakan komersil 0%.  Hasil uji statistik menunjukan adanya perbedaan yang nyata.  Nilai signifikan p <.0002 (<.05).  Parameter kualitas air yang diukur selama penelitian adalah suhu 26ºC.Keywords: larva ikan betta, pakan alami, Alona sp., kelangsungan hidup


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