Long-term evaluation of pup growth and preweaning survival rates in subantarctic fur seals, Arctocephalus tropicalis, on Amsterdam Island

2003 ◽  
Vol 81 (7) ◽  
pp. 1222-1232 ◽  
Author(s):  
Magaly Chambellant ◽  
Gwénaël Beauplet ◽  
Christophe Guinet ◽  
Jean-Yves Georges
Keyword(s):  
Growth Rate ◽  
Food Availability ◽  
Survival Rates ◽  
Birth Date ◽  
Growth And Survival ◽  
Fur Seals ◽  
Pup Growth ◽  
Sst Gradient ◽  
Subantarctic Fur Seals ◽  
Arctocephalus Tropicalis

This study is the first to investigate pup preweaning growth and survival rates over seven consecutive breeding seasons in subantarctic fur seals, Arctocephalus tropicalis, on Amsterdam Island, southern Indian Ocean. Growth and survival were studied in relation to year and pup sex, birth date, birth mass, and growth rate at 60 days of age. The pup growth rate decreased over the 7-year study period and was the lowest ever found in otariids, which suggests that lactating females experience constant low food availability. Male and female pups grew and survived at similar rates. Pups that were heavier at birth grew faster and exhibited better early survival (i.e., the first 2 months of life) than pups that were lighter at birth. However, no such relationship was detected for late survival (i.e., from 2 months to weaning) in this long-lactating species. No relationship was found between pup growth rate, pup survival rate, and sea-surface temperature (SST) gradient during the study period, especially during the later years of good trophic conditions (i.e., a high SST gradient). Such dissociations suggest that variation in food availability may not be the only factor influencing pup performance until weaning. We therefore propose that the subantarctic fur seal population is reaching its carrying capacity and that a density-dependent effect is occurring on Amsterdam Island.

Age structure, growth, and demographic parameters in breeding-age female subantarctic fur seals, Arctocephalus tropicalis

2004 ◽  
Vol 82 (7) ◽  
pp. 1043-1050 ◽  
Author(s):  
Willy Dabin ◽  
Gwénaël Beauplet ◽  
Enrique A Crespo ◽  
Christophe Guinet
Keyword(s):  
Age Distribution ◽  
Reproductive Rate ◽  
Reproductive Period ◽  
Demographic Parameters ◽  
Island Population ◽  
Female Population ◽  
Regulatory Processes ◽  
Fur Seals ◽  
Subantarctic Fur Seals ◽  
Arctocephalus Tropicalis

Age distribution was estimated for 108 breeding-age female subantarctic fur seals, Arctocephalus tropicalis (Gray, 1872), sampled during the 1999–2000 breeding season on Amsterdam Island, southern Indian Ocean. The growth features were described and demographic parameters assessed from transversal life tables constructed for this female population. The breeding females had a longer mean body length than was observed for other breeding populations of the same species. These females also showed a later start to reproduction (6 years old), a lower overall age-specific reproductive rate (R6–16 = 48.0%), and a lower survival in older age classes (>13 years). Females reproduced up to a maximum age of 16 years, with none older than 19 years observed in the colony, suggesting an apparent senescence in the population. This consequently reduced the theoretical reproductive period of the females, which has led to a lower number of reproductive outputs per individual (i.e., 3.65 weaned pups per female throughout its reproductive life). Although such differences between islands may be related to genotypic traits, these results are consistent with low food availability and suggest that density-dependent regulatory processes operate on the Amsterdam Island population.

Milking Strategy in Subantarctic Fur Seals Arctocephalus tropicalis Breeding on Amsterdam Island: Evidence from Changes in Milk Composition

2001 ◽  
Vol 74 (4) ◽  
pp. 548-559 ◽  
Author(s):  
Jean‐Yves Georges ◽  
René Groscolas ◽  
Christophe Guinet ◽  
Jean‐Patrice Robin
Keyword(s):  
Milk Composition ◽  
Fur Seals ◽  
Subantarctic Fur Seals ◽  
Arctocephalus Tropicalis

scholarly journals Effect of Hardness in 3 ppt of Water Salinity on growth and survival rates of Barb Fish (Barbus conhonius Hamilton-Buchanan)

2007 ◽  
Vol 4 (1) ◽  
pp. 17 ◽  
Author(s):  
Kukuh Nirmala ◽  
R. Wulandari ◽  
D. Djokosetiyanto
Keyword(s):  
Growth Rate ◽  
Survival Rate ◽  
Survival Rates ◽  
Water Hardness ◽  
Water Salinity ◽  
Daily Growth Rate ◽  
Daily Growth ◽  
Growth And Survival

<p>This study was conducted to determine the effect of hardness on growth and survival rate of barb fish (<em>Barbus conchonius</em> Hamilton-Buchanan) reared in the 3 ppt of water salinity.  Fish were reared in three different hardnesses, i.e., 54, 72,<sub> </sub>and 90 mg/L CaCO<sub>3 </sub>for 30 days.  The results of study showed that fish reared in water hardness of 72 mg/L CaCO<sub>3</sub> had higher daily growth rate (1.15%) compared with other treatments.  Daily growth rate of fish reared in water hardness of 54 and 90 mg/L CaCO<sub>3</sub> were 0.76 and 0.37%, respectively.  There was no effect of hardness on survival rate of barb fish.</p> <p>Keywords: barb fish, <em>Barbus conchonius</em>,  hardness, salinity</p> <p> </p> <p>ABSTRAK</p> <p>Penelitian ini bertujuan untuk mengetahui pengaruh kesadahan yang berbeda terhadap laju pertumbuhan dan tingkat kelangsungan hidup ikan barbir (<em>Barbus conchonius</em> Hamilton-Buchanan) yang dipelihara <a name="OLE_LINK2"></a><a name="OLE_LINK1">pada air bersalinitas 3 ppt.  </a>Ikan dipelihara dalam 3 tingkat kesadahan yang berbeda, yaitu 54 mg/L CaCO<sub>3</sub>, 72 mg/L CaCO<sub>3</sub>,<sub> </sub>dan 90 mg/L CaCO<sub>3 </sub>selama 30 hari.  Hasil penelitian menunjukkan bahwa laju perumbuhan harian tertinggi diperoleh pada ikan yang dipelihara pada kesadahan 72 mg/L CaCO<sub>3 </sub>(1,15%) dibandingkan dengan perlakuan lainnya. Laju pertumbuhan harian ikan yang dipelihara pada kesadahan 54 dan  90 mg/L CaCO<sub>3</sub> masing-masing mencapai 0,76% dan 0,37%.  Kelangsungan hidup ikan barb tidak dipengaruhi oleh kesadahan.</p> <p>Kata kunci: ikan barbir, <em>Barbus conchonius</em>, kesadahan, salinitas</p>

scholarly journals EFFECTS OF FEED ON THE SURVIVAL RATE, GROWTH RATE AND METAMORPHOSIS TIME OF THE WHITE LEG SHRIMP LARVAE (Litopenaeus vannamei Boone, 1931) AT ZOEA STAGE

2018 ◽  
Vol 54 (4A) ◽  
pp. 205
Author(s):  
Nguyen Van Cong
Keyword(s):  
Growth Rate ◽  
Survival Rate ◽  
Litopenaeus Vannamei ◽  
Survival Rates ◽  
Stocking Density ◽  
Growth And Survival ◽  
Study Results

The larvae of white leg shrimp (Litopenaeus vannamei Boone, 1931) at phase nauplii 6 fed with a stocking density of 150 pcs per litre and 3 formula including formula 1 with dry microalgae Spirulina + artemia as main ingredients, formula 2 with microalgae Thalasiosira weissflogii + artemia as main ingredients and formula 3 with microalgae Thalasiosira pseudonana + artemia as main ingredients. Experiments were carried out in 18 tanks fifty-litre composite at Quang Binh branch of C.P Vietnam Corporation. The study results show that, with formula 3, white leg shrimps larvae at zoea stage have the highest growth and survival rates (86.57 %), followed by formula 2 (76.03 %) and finally formula 1 (67.90 %). White leg shrimps larvae at zoea stage in formula 3 have the shortest metamorphosis time (78.61 hours), followed by formula 2 (83.25 hours) and the longest in formula 1 (94.10 hours).

Subantarctic fur seals Arctocephalus tropicalis at Heard Island

Polar Biology ◽  
1989 ◽  
Vol 9 (5) ◽  
pp. 337-339 ◽  
Author(s):  
S. D. Goldsworthy ◽  
P. D. Shaughnessy
Keyword(s):  
Fur Seals ◽  
Heard Island ◽  
Subantarctic Fur Seals ◽  
Arctocephalus Tropicalis

scholarly journals The Effect of Potassium Diformate Addition to Feed on Growth and Survival Rates of Common Carp (Cyprinus carpio L.)

2020 ◽  
pp. 1-8
Author(s):  
Ayi Yustiati ◽  
Mahmud Sa’id ◽  
. Junianto ◽  
Ibnu Bangkit Bioshina Suryadi
Keyword(s):  
Growth Rate ◽  
Survival Rate ◽  
Common Carp ◽  
Survival Rates ◽  
Stocking Density ◽  
Good Effect ◽  
Optimal Dosage ◽  
Daily Growth Rate ◽  
Daily Growth ◽  
Growth And Survival

This research aimed to determine the optimal dosage of potassium diformate addition to commercial feed in order to increase the growth and survival rate of common carp seeds. The method used in this research was experimental in a completely randomized design (CRD) consisting of five treatments and four replications. The treatments used were A (control), B with addition of potassium diformate (0.2%), C (0.3%), D (0.4%), and E (0.5%). For test fish, there were 200 of Common carp seeds with a size of 2-3 cm. The media used was 20 aquariums with a size of 40x30x40 cm3 and a stocking density of 10 individuals/aquarium. The rearing period was 35 days and the amount of feed given was 3% of the fish body weight. The parameters observed included water quality (temperature, pH, and dissolved oxygen) which were observed every 7 days for 35 days. Other parameters  monitored were daily growth rate, survival rate, feed efficiency, and the acidity level of the intestine. The results showed that 0.3% addition of potassium diformate gave the best results with a daily growth rate value of 3.21%, highest survival of 98%, efficiency of feed utilization of 64.83%, and a decrease in intestinal pH which helped the process of protein absorption in the fish body. In conclution, the addition of potassium diformate has good effect on growth and survival rates of common carp.

Sign in / Sign up

Export Citation Format

Share Document