scholarly journals Early development, survival and growth rates of the giant clam Tridacna crocea (Bivalvia: Tridacnidae)

2012 ◽  
Vol 60 (2) ◽  
pp. 127-133 ◽  
Author(s):  
Miguel Mies ◽  
Felipe Braga ◽  
Marcello Santos Scozzafave ◽  
Daniel Eduardo Lavanholi de Lemos ◽  
Paulo Yukio Gomes Sumida
Keyword(s):  
Growth Rates ◽  
Larval Mortality ◽  
Larval Growth ◽  
Isochrysis Galbana ◽  
Giant Clam ◽  
Daily Growth ◽  
Growth And Survival ◽  
Food Industries ◽  
Survival And Growth ◽  
Tridacna Crocea

Tridacnid clams are conspicuous inhabitants of Indo-Pacific coral reefs and are traded and cultivated for the aquarium and food industries. In the present study, daily growth rates of larvae of the giant clam Tridacna crocea were determined in the laboratory during the first week of life. Adults were induced to spawn via intra-gonadal serotonin injection through the byssal orifice. After spawning oocytes were collected, fertilized and kept in 3 L glass beakers and raceways treated with antibiotics to avoid culture contamination. Larvae were fed twice with the microalga Isochrysis galbana and zooxanthellae were also offered twice during the veliger stage (days 4 and 6). Larval length was measured using a digitizing tablet coupled to a microcomputer. Larval mortality was exponential during the first 48 hours of life declining significantly afterwards. Mean growth rate was 11.3 μm day-1, increasing after addition of symbionts to 18.0 μm day-1. Survival increased to ca. 75% after the addition of zooxanthellae. The results describe the growth curve for T. crocea larvae and suggest that the acquisition of symbionts by larvae may be useful for larval growth and survival even before larvae have attained metamorphosis.

scholarly journals Moonlight enhances growth in larval fish

2020 ◽  
Author(s):  
Jeffrey Shima ◽  
SE Swearer
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Larval Fish ◽  
Fish Larvae ◽  
Larval Growth ◽  
Negative Influence ◽  
Life History Strategies ◽  
Foraging Efficiency ◽  
Daily Growth ◽  
Pelagic Larvae

© 2018 by the Ecological Society of America Moonlight mediates trophic interactions and shapes the evolution of life-history strategies for nocturnal organisms. Reproductive cycles and important life-history transitions for many marine organisms coincide with moon phases, but few studies consider the effects of moonlight on pelagic larvae at sea. We evaluated effects of moonlight on growth of pelagic larvae of a temperate reef fish using “master chronologies” of larval growth constructed from age-independent daily increment widths recorded in otoliths of 321 individuals. We found that daily growth rates of fish larvae were enhanced by lunar illumination after controlling for the positive influence of temperature and the negative influence of cloud cover. Collectively, these results indicate that moonlight enhances growth rates of larval fish. This pattern is likely the result of moonlight's combined effects on foraging efficiency and suppression of diel migrations of mesopelagic predators, and has the potential to drive evolution of marine life histories.

scholarly journals Moonlight enhances growth in larval fish

2020 ◽  
Author(s):  
Jeffrey Shima ◽  
SE Swearer
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Larval Fish ◽  
Fish Larvae ◽  
Larval Growth ◽  
Negative Influence ◽  
Life History Strategies ◽  
Foraging Efficiency ◽  
Daily Growth ◽  
Pelagic Larvae

© 2018 by the Ecological Society of America Moonlight mediates trophic interactions and shapes the evolution of life-history strategies for nocturnal organisms. Reproductive cycles and important life-history transitions for many marine organisms coincide with moon phases, but few studies consider the effects of moonlight on pelagic larvae at sea. We evaluated effects of moonlight on growth of pelagic larvae of a temperate reef fish using “master chronologies” of larval growth constructed from age-independent daily increment widths recorded in otoliths of 321 individuals. We found that daily growth rates of fish larvae were enhanced by lunar illumination after controlling for the positive influence of temperature and the negative influence of cloud cover. Collectively, these results indicate that moonlight enhances growth rates of larval fish. This pattern is likely the result of moonlight's combined effects on foraging efficiency and suppression of diel migrations of mesopelagic predators, and has the potential to drive evolution of marine life histories.

scholarly journals Influence of Different Algal Diets on Larval Growth Rates in the Marine Serpulidae Polychaete Worm Spirobranchus kraussii

2019 ◽  
Vol 77 (2) ◽  
pp. 93-98
Author(s):  
Fatemeh Lavajoo
Keyword(s):  
Survival Rate ◽  
Growth Rates ◽  
Larval Growth ◽  
Single Species ◽  
Growth And Survival ◽  
Food Size ◽  
Algal Diets ◽  
Alternative Sources ◽  
Newly Hatched Larvae ◽  
Algal Diet

Abstract Effects of food availability on larval growth and survival of Spirobranchus kraussii were studied by feeding larvae different algal diets. Newly hatched larvae of S. kraussii were fed four different marine microalgae species, singly and in various mixtures. The best growth was observed when fed C. vulgaris, N. oculata as a single species and mixed-algal diet during day 15 after fertilization. Mortality was low for larvae (max. 5%); survival rate more than 95%. These results suggest that S. kraussii larvae have the capacity to feed using alternative sources of energy, and food size and quality can affect their growth and sustainability.

scholarly journals Live and formulated diet evaluation through initial growth and survival of jundiá larvae, Rhamdia quelen

2003 ◽  
Vol 60 (4) ◽  
pp. 615-619 ◽  
Author(s):  
Paulo César Falanghe Carneiro ◽  
Jorge Daniel Mikos ◽  
Marianne Schorer ◽  
Paulo Roberto Campagnoli Oliveira Filho ◽  
Fabiano Bendhack
Keyword(s):  
Fish Larvae ◽  
Larval Growth ◽  
Initial Growth ◽  
Growth And Survival ◽  
Formulated Diets ◽  
Fish Feeds ◽  
Rhamdia Quelen ◽  
Survival And Growth ◽  
Effect Of Feeding

Live diet (LD) dependence and the lack of suitable formulated diets (FD) are major constraints for the expansion of larviculture of many fish species. The low digestibility and nutritional quality of FD are factors that might explain their failure as a stand-alone starter food. To determine whether FD in combination with LD (zooplankton) may efficiently increase larval growth and survival of jundiá (Rhamdia quelen), when compared to fish fed by either types of diet alone, jundiá larvae (5.57 mm; 1.41 mg) were initially stocked into 12 10-L aquaria (100 larvae per aquarium). Replicate groups (n=4) were fed ad libitum one of the three diets for 20 (when fed FD) or 48 days (when fed LD or the combined diets). Larvae fed FD alone presented significantly lower survival and growth rates as compared to larvae fed LD or a combination of both (co-fed). In addition, co-fed larvae grew better (170 mg) in relation to those fed solely with LD (110 mg). Such better performance of combined feeding indicates that most of the required nutrients are in balance when both diet sources are included. More can be learned about fish larvae nutrition by further testing the effect of feeding combined diets, which include zooplankton, than only testing new ingredients or protein sources commonly used in the elaboration of juvenile or adult fish feeds.

Feeding, Growth, and Survival of Atlantic Cod (Gadus morhua) Larvae Reared in Replicate Plastic Enclosures

1993 ◽  
Vol 50 (5) ◽  
pp. 913-924 ◽  
Author(s):  
Håkon Otterå
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Brachionus Plicatilis ◽  
Larval Mortality ◽  
Larval Density ◽  
Larval Growth ◽  
Stocking Density ◽  
Gut Content ◽  
Growth And Survival ◽  
Rearing Conditions

Feeding, growth, and survival of Atlantic cod (Gadus morhua) larvae were examined during their first 2 mo of life. The experiment was carried out in eight plastic enclosures of 10 m3 volume each. Larval cod, at an initial stocking density of 10 larvae/L, were fed rotifers (Brachionus plicatilis) and natural zooplankton collected from the sea. The enclosures replicated well with regard to hydrography, feeding conditions, and larval growth and survival. Larval mortality was low during the first month, with a mean mortality rate (Z) of 0.02/d. Growth, however, was very slow and mortality increased significantly after about 4 wk, possibly due to starvation. Brachionus plicatilis dominated the gut content during the first 3–4 wk. The zooplankton concentration averaged 15–80 rotifers/L during the first 2 wk, which seemed to be insufficient under the present rearing conditions. Most of the larvae were distributed in the upper parts of the rearing enclosures, while rotifers were distributed deeper. This, together with the high larval density, inadequate rotifer enrichment, and low temperature probably amplified the unfavourable feeding conditions.

Predicting survival and growth rates for individual loblolly pine trees from light capture estimates

2002 ◽  
Vol 32 (11) ◽  
pp. 1970-1983 ◽  
Author(s):  
David W MacFarlane ◽  
Edwin J Green ◽  
Andreas Brunner ◽  
Harold E Burkhart
Keyword(s):  
Loblolly Pine ◽  
Growth Rates ◽  
Survival Probability ◽  
Basal Area ◽  
Site Index ◽  
Planting Density ◽  
Growth And Survival ◽  
Survival And Growth ◽  
Light Capture ◽  
Stand Conditions

Light capture estimates from models can be related to survival and growth rates and may provide new ways to model forest dynamics. However, relationships between light capture, growth, and survival should vary widely with tree age, site conditions, and stand density, so predictions from light capture models need to be tested over a range of stand conditions. We used the tRAYci stand light model (A. Brunner. 1998. For. Ecol. Manage. 107: 19–46) to estimate weighted leaf area (WLA), an estimate of annual light capture, for every tree, in 36 even-aged loblolly pine (Pinus taeda L.) stands, representing different combinations of site index and planting density, over an 8-year period. We also developed regression equations relating light capture estimates to height growth, basal area growth, stem volume growth, and survival probability for individual trees at different ages, sites, and planting densities. Our results suggest a significant correlation between estimates of WLA and tree growth and survival rates, and that the tRAYci model is robust across a range of stand conditions. An important finding was that WLA was a better predictor of survival probability than measured basal area increment. Effects of site index, age, and planting density on light capture – growth relationships are also discussed.

Development of black soldier fly larvae (Diptera: Stratiomyidae) on seafood wastes

2019 ◽  
Vol 5 (4) ◽  
pp. 313-319 ◽  
Author(s):  
J. Villazana ◽  
A. Alyokhin
Keyword(s):  
Sea Urchin ◽  
Sea Cucumber ◽  
Larval Mortality ◽  
Larval Growth ◽  
Published Data ◽  
Black Soldier Fly ◽  
Growth And Survival ◽  
Short Period ◽  
Similar Materials ◽  
Black Soldier Fly Larvae

The black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae) is well suited for remediating biological waste. Larvae of this species are nutrient rich, grow rapidly, and convert organic wastes while suppressing pathogens and pests. Therefore, they could be used in waste management systems and as feed for livestock and in aquaculture. The goal of this study was to test suitability of several seafood wastes from Maine processing facilities for H. illucens development in order to find alternative venues for their utilization. The following substrates were tested under laboratory conditions: dry sea cucumber, wet sea cucumber, crab meal, finfish, dry quahog, wet quahog, and sea urchin (‘wet’ and ‘dry’ refer to the original condition of the wastes while their moisture levels were similar during the experiment). H. illucens eggs were placed on wax paper above each substrate, and larval growth and survival to pupation were measured. Based on the numbers and weights of surviving larvae, substrates potentially suitable for H. illucens rearing included finfish trimmings, wet sea cucumber, dry quahog, and sea urchin. Crab meal produced large larvae (0.091±0.021 g [mean ± SE], compared to experiment-wide mean of 0.064±0.007 g) in a relatively short period of time. However, larval mortality was very high, with only 4.7±1.17 larvae surviving to prepupae, compared to experiment-wide mean of 9.78±0.63 larvae. There were dramatic differences in seemingly similar materials. On wet sea cucumber, 28.82±1.49 larvae per replication survived to pre-pupae, while on dry sea cucumber the number was only 0.33±0.01. On wet and dry quahog, the numbers of surviving larvae were 1.83±0.60 and 10.1±1.97, respectively. This highlights the importance of thorough testing of specific substrates instead of extrapolating from published data.

scholarly journals Development and individual identification of captive Ziegler’s crocodile newt Tylototriton ziegleri

2021 ◽  
pp. 14-17
Author(s):  
Josh Coppola
Keyword(s):  
Growth Rates ◽  
Larval Mortality ◽  
Larval Growth ◽  
Stocking Density ◽  
Limited Range ◽  
Individual Identification ◽  
Computer Assisted ◽  
Egg Hatch ◽  
In Captivity ◽  
Identification Software

Tylototriton ziegleri is a newt native to Vietnam with a very limited range and assessed as Vulnerable by the IUCN. It is rarely found in captivity. Larval husbandry, based on field conditions, had mixed success with a high proportion of egg hatch and relatively rapid larval growth rates but also substantial larval mortality, probably due to high stocking density. Larvae started to hatch after 23 days and after 77-79 days had metamorphosed at a mean mass of 1.6 g; juveniles grew at an average of about 0.3 g/month. The primary animal carer was able to use wart patterns to distinguish between four individuals but scope for use on a larger scale was not supported when tested using computer-assisted individual identification software (WildID) or expert observers.

The missing links: larval and post-larval development of the ascoglossan opisthobranch Elysia viridis

2000 ◽  
Vol 80 (6) ◽  
pp. 1087-1094 ◽  
Author(s):  
Cynthia D. Trowbridge
Keyword(s):  
Larval Development ◽  
Growth Rates ◽  
Shell Length ◽  
Larval Growth ◽  
Model Organism ◽  
Larval Life ◽  
Codium Fragile ◽  
Planktotrophic Larvae ◽  
Algal Diet ◽  
Better Than

The stenophagous ascoglossan (=sacoglossan) opisthobranch Elysia viridis has long been a model organism for the study of endosymbiosis or kleptoplasty as well as one of the few herbivores to consume the introduced green macroalga Codium fragile on European shores. Larval and post-larval dynamics of the ascoglossan were investigated. Planktotrophic larvae of E. viridis grew at 5–10 μm d−1 (shell length) at 15°C on a unicellular algal diet (the cryptophyte Rhodomonas baltica); larvae became competent one month post-hatching. Effective feeding and chloroplast acquisition typically started within 2–3 d of metamorphosis. Slugs grew about 8 mm in the first month of post-larval life. During this period, juveniles held in the light did not grow faster or survive better than conspecifics held in the dark; thus, functional kleptoplasty did not occur during first three weeks of benthic life. While larval growth rates and the nature of metamorphic cues are consistent with those of many other opisthobranch species with planktotrophic larvae, measures of post-larval growth—particularly as it pertains to kleptoplasty—is a new contribution to opisthobranch biology.

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