scholarly journals CRECIMIENTO Y SUPERVIVENCIA DEL MEJILLÓN DE AGUA DULCE, ANODONTITES TRAPESIALIS (LAMARCK 1819), EN UN FLUJO A TRAVÉS DEL SISTEMA PARA LA EXPLOTACIÓN A LARGO PLAZO

2011 ◽  
Vol 3 ◽  
pp. 43
Author(s):  
Ricardo C. Lima ◽  
Angela T. Paes ◽  
Wagner E. P. Avelar

As with other freshwater mussels, Anodontites trapesialis is an endangered and threatened species. Artificial culture has been strongly recommended in recovery plans as a strategy to bolster declining populations, as well as the reintroduction of species to sites within their historic ranges. Our project compares two methods of adult animal management: buried and suspended, focusing on growth and survival of A. trapesialis in a captive environment. Animals were fed with Chlamydomonas spp. After 120 days, weight (soft and hard body) increased by 2.1% in the suspended group and decreased by 1.4% in the buried group. Suspended animals showed higher survival rates than those that were buried. The information provided may be of particular interest to develop future conservation measures for this and other similar endangered species. Así como otras especies de almejas de agua dulce, Anodontites trapesialis se encuentra en peligro y amenazada de extinción. El cultivo artificial ha sido muy recomendado en los planes de recuperación como una estrategia para mejorar las cifras de población en declive, así como la reintroducción de especies a sitios dentro de sus rangos históricos. Nuestro estudio compara dos métodos de manejo de animales adultos, enterrados y suspendidos, con un enfoque en el crecimiento y la supervivencia de A. trapesialis en un ambiente de cautiverio. Los animales fueron alimentados con Chlamydomonas spp. Al comparar los porcentajes de peso corporal (concha y tejido blando) después de 120 días, un aumento medio del 2.1% se observó en el grupo suspendido y una pérdida media del 1.4% en el grupo enterrado. Los animales suspendidos tuvieron mejores tasas de supervivencia que aquellos que fueron enterrados. La información proporcionada puede ser de especial interés para el desarrollo de las futuras medidas de conservación para esta y otras especies similares en peligro de extinción.

2013 ◽  
Vol 75 (4) ◽  
pp. 532-542 ◽  
Author(s):  
Caitlin S. Carey ◽  
Jess W. Jones ◽  
Eric M. Hallerman ◽  
Robert S. Butler

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).


2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Anak Agung Alit ◽  
Ketut Maha Setiawati ◽  
Tony Setia Dharma

ABSTRACT Feed management is a critical factor in the nursery activities because food serves as an energy for growth and survival rates. The study aimed to determine the best feeding to improve growth and survival rates. Cultured of coral trout grouper seeds were used for this research in 9 fiber tubs each of  0.8 tonnes of sea water volume with 3 treatments and 3 replicates. The feeding treatments were (a) commercial feeding pelle; (b) trash fish; and (c) feeding combinations (50% pellets and 50% trash fish). The initial length of coral trout grouper seeds were 3 cm long. The pellet used was a commercial pellet with dose of 5-10% biomass, while the trash fish was clupeid fish. Feeding times were twice a daya at 08:00 and 16:00 local time. A complete random design was used as an experiment design. Data was analysed using ANOVA and descriptive statistics. Water qualities during larva rearing included water temperature, pH, salinity, DO, ammonia, nitrite, and phosphate. The results showed that growth dan survical rates was significantly affected by combination feeding method (50% pellet and 50% trash fish) with growth rate of 0.08% cm/day and survival rate of 60.20±2.34%. Keywords: Feed, trash fish, juvenile coral trout grouper, growth, and survival.


Author(s):  
Jana Niedobová ◽  
Vladimír Hula ◽  
Pavla Šťastná

Collecting of Carabidae was conducted using pitfall traps at four sites. The first two sites (T1 + T2) were at the slope of Macošská stráň and the other two sites (T3 + T4) at the slope of Vilémovická stráň. The study was done in 2008 and 2009. At Macošská stráň in 2008, 21 species of Carabidae with the total number of 228 individuals were found and in 2009, 18 species of the total number of 116 specimens were collected. At Vilémovická stráň in 2008, 22 species of Carabidae with the total number of 1977 specimens were found and in 2009, 21 species of the total number of 623 specimens were caught. In terms of classification of relictness, Macošská stráň in 2008 was dominated by species of adaptable group A (60%), species of eurytop group (E) were represented by 35% and of relic group (R) by 5%. In 2009, the same representation of species of groups A and E (47%) were found and the species of group R were represented by 6%. Vilémovická stráň in 2008 was dominated by species of group A (52%), species of group E were represented by 43% and of group R by 5%. In 2009 also dominated species of group A (54%), species of group E were represented by 41% and of group R by 5%. In the studied area we reported four endangered species of Carabidae protected by Law (No. 395/1992 Coll.) as amended, these were Calosoma auropunctatum (critically endangered), Brachinus crepitans, Carabus ullrichii and Cicindela campestris (endangered) and two species listed under the Red List of Threatened Species of the Czech Republic (Veselý et al., 2005). One of the species is listed as vulnerable (Calosoma auropunctatum) and one as near endangered (Carabus cancellatus). Another significant species found on the monitored sites was Aptinus bombarda.


1988 ◽  
Vol 45 (8) ◽  
pp. 1490-1494 ◽  
Author(s):  
Eric A. Parkinson ◽  
Kanji Tsumura

Coho (Oncorhynchus kisutch) and kokanee salmon (O. nerka) were sterilized using 17α-methyltestosterone treatments and released into a lacustrine environment. The treatment appeared to be successful and sizes at capture were similar for treated and control fish. Return rates of hormone-treated groups of fish were much lower than those of the control groups. Differences in return rates were assumed to be due to differences in survival rates but the possibility of differential vulnerability to the capture gear could not be ruled out. The proportion of treated kokanee in the catch increased with age, indicating that treated kokanee survived beyond the normal life span of the species.


1989 ◽  
Vol 46 (8) ◽  
pp. 1323-1328 ◽  
Author(s):  
Michael G. Fox

I investigated the influence of food availability on growth and survival of walleye (Stizostedion vitreum vitreum) fry stocked in six fertilized experimental ponds (density 40 fish∙m−3) and reared for 8 wk. Walleye fed largely on chironomid larvae and cyclopoid copepods in weeks 1 and 2, and chironomids thereafter. Prey choice and consumption were strongly influenced by chironomid biomass in the benthos, and to a lesser extent by zoo-plankton density. Weekly length increase of the populations and mean length in week 7 were significantly correlated with chironomid benthic biomass and mean prey length. Chironomid biomass and density of large zoo-plankton together explained 56% of the variation in the weekly population growth rate. Despite obvious food limitation in the second half of the experiment, pond survival rate was not significantly correlated with mean prey density, mean stomach fullness, or percentage of fish with empty stomachs. The results indicate that juvenile walleye growth can be regulated by the density and size of available prey. Prey availability apparently does not regulate short term juvenile walleye survival rates after the period around first feeding.


Oryx ◽  
1992 ◽  
Vol 26 (4) ◽  
pp. 202-204 ◽  
Author(s):  
J. L. Cloudsley-Thompson

While Saudi Arabia has recognized the dangers of uncontrolled hunting and has introduced conservation measures in its own territory, prominent members of that kingdom are killing large numbers of game, including endangered species, in neighbouring countries. In this report the author presents evidence of the devastation caused by Saudi hunters in the Sudan. While the latter country has outlawed hunting, enforcing the law against Saudi nationals is fraught with difficulties.


2019 ◽  
Vol 98 ◽  
pp. 12005
Author(s):  
Yongwen Gao ◽  
Joseph Gilbertson ◽  
Hongyan Zhang

The Pacific razor clam fishery in Washington State has been co-managed by the coastal Indian Tribes and the state, but little is known about the growth and population structure of the clams due to difficulties of tagging and monitoring. Here we report the results of a pilot study using stable isotope ratios (δ13C and δ18O) of razor clam shells collected in two groups (juvenile vs. adult) and from two sites (Kalaloch Beach and Roosevelt Beach) where distinct biological differences in clam growth and survival rates were observed. The δ13C values of razor clam shells ranged from -2.9 to -0.3‰, whereas δ18O values of the same samples ranged from -2.2 to +1.4‰. Between the two sites there were significant differences in δ13C values especially for juvenile clams. The δ18O profiles from two representative shells demonstrated similar patterns of rapid growth as juveniles and seasonal patterns throughout the life span. Profiles of δ13C were sinusoidal but did not show seasonality and signatures of ocean acidification. We concluded that stable isotope analysis of razor clam shells is a potential new tool in shellfish research and management.


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