Effect of starvation on condition and growth of juvenile plaice Pleuronectes platessa: nursery habitat quality assessment during the settlement period

In order to assess the effect of feeding deprivation on growth and condition of field-caught newly settled juvenile plaice Pleuronectes platessa, a 3 week starvation experiment was conducted and changes in RNA/DNA ratio, Fulton's K condition index and recent otolith growth were measured. Fed ad libitum and starved fish were analysed after 0, 1, 2, 3, 4, 5, 7, 9, 14, 16 and 22 days of starvation. In parallel, field newly settled juvenile plaice were collected weekly over the settlement period (between April and May 2005) in the adjacent intertidal zone of the Canche estuary (eastern English Channel, France) and fish performances were estimated. After starvation day 4, Fulton's K condition index and RNA/DNA ratio of juvenile plaice significantly differed between treatments while recent otolith growth differed between treatments after day 9 of the experiment procedure. Results indicate that the three biological parameters are sensitive indices and can be used to accurately assess nutritional condition of wild juvenile fish. Values of 0.32 for RNA/DNA, 0.83 mg. mm−3 for Fulton's K index, and 3.99 µm for recent otolith daily growth were defined as critical threshold values below which juvenile plaice can be classified as ‘starving'. When comparing these experimental values with those from field-caught newly settled juvenile plaice, less than 1% of wild individuals can be classified as ‘starving' whatever the index. Our results suggest that feeding conditions throughout the settlement period on the Canche intertidal nursery ground are favourable to juvenile plaice development and survival, and hence to the recruitment success.

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A comparative study on the nursery culture of hatchery-reared sub-adult cupped oyster, Crassostrea iredalei (Faustino, 1932), in an earthen pond and a mangrove canal

Fisheries & Aquatic Life ◽

10.2478/aopf-2018-0024 ◽

2018 ◽

Vol 26 (4) ◽

pp. 217-222

Author(s):

Premwadee Chueachat ◽

Woraporn Tarangkoon ◽

Suwat Tanyaros

Keyword(s):

Growth Rate ◽

Comparative Study ◽

Condition Index ◽

Daily Growth ◽

Nursery Culture ◽

Absolute Growth Rate ◽

Significant Difference ◽

Adult Oyster ◽

Absolute Growth ◽

The Mean

Abstract A comparative study on the nursery culture of the spat of the tropical oyster, Crassostrea iredalei, in an earthen pond and a mangrove canal was conducted over two months. The results revealed no differences in the absolute growth rate determined by shell width between the two culture sites (P < 0.05). Sub-adult oysters cultured in the mangrove canal showed a higher absolute growth rate in shell length and a higher daily growth rate than the oysters cultured in the earthen pond (P < 0.05). The mean survival rate of sub-adult oysters cultured in the earthen pond (99.8 ± 0.2%) was significantly higher than for those cultured in the mangrove canal (66.7 ± 31.4%). Decreased density from the loss of sub-adult oyster nursery culture in the mangrove canal led to higher growth performance than in the earthen pond. However, no difference was found for the fraction of oysters larger or smaller than 5 cm for the two culture sites (P < 0.05). A significant difference was noted in the Condition Index (CI) between the two culture sites (P < 0.05). The high primary productivity in mangroves is a major supporter of higher CI in sub-adult oysters cultured in mangrove canals versus in earthen ponds. Water exchange in the earthen pond to maintain calcium and magnesium concentrations resulted in no differences in the shell compressibility of sub-adult oysters compared with those cultured in the mangrove canal.

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Predation on meiofauna by juvenile fish in a Western Mediterranean flatfish nursery ground

Marine Biology ◽

10.1007/bf00394104 ◽

1984 ◽

Vol 82 (2) ◽

pp. 209-215 ◽

Cited By ~ 49

Author(s):

L. Tito de Morais ◽

J. Y. Bodiou

Keyword(s):

Juvenile Fish ◽

Western Mediterranean ◽

Nursery Ground

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Daily Growth Increments in Otoliths of Starry Flounder (Platichthys stellatus) and the Influence of Some Environmental Variables in Their Production

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f82-127 ◽

1982 ◽

Vol 39 (7) ◽

pp. 937-942 ◽

Cited By ~ 66

Author(s):

Steven E. Campana ◽

John D. Neilson

Keyword(s):

Environmental Conditions ◽

Environmental Variables ◽

Daily Basis ◽

Otolith Growth ◽

Daily Growth ◽

Environmental Regime ◽

Starry Flounder ◽

Daily Increments ◽

Growth Increments ◽

Platichthys Stellatus

Tetracycline injected into juvenile starry flounders (Platichthys stellatus) was incorporated into the periphery of the sagittal otoliths within 24 h. The resulting band, visible under ultraviolet light, was used as a dated mark on the otolith growth increments. This technique was used to verify that increments were laid down on a daily basis, both in field and laboratory environments. Subdaily increments were visible in otoliths of fishes reared under most environmental conditions. The production of daily increments in juvenile starry flounders preconditioned to a natural environmental regime was unaffected by photoperiod or temperature fluctuation, suggesting the presence of an internal circadian rhythm.Key words: starry flounder, Platichthys stellatus; otoliths, daily rings, growth increments, circadian, tetracycline

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Otoliths of Chinook Salmon (Oncorhynchus tshawytscha): Daily Growth Increments and Factors Influencing Their Production

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f82-180 ◽

1982 ◽

Vol 39 (10) ◽

pp. 1340-1347 ◽

Cited By ~ 96

Author(s):

John D. Neilson ◽

Glen H. Geen

Keyword(s):

Chinook Salmon ◽

Oncorhynchus Tshawytscha ◽

Fish Length ◽

Feeding Frequency ◽

Otolith Growth ◽

Increment Width ◽

Daily Growth ◽

Factors Affecting ◽

Growth Increments ◽

Otolith Increment

The effects of photoperiod, feeding frequency, and water temperature on formation of otolith daily growth increments in juvenile chinook salmon (Oncorhynchus tshawytscha) were examined. Feeding frequency influenced both increment number and width, whereas photoperiod and temperature affected only increment width. Fish fed once/24 h produced one increment every 24 h on average, while fish fed 4 times/24 h produced more than one increment every 24 h. Wider increments were produced in fish exposed to warmer water (11 °C) or 24 h of darkness. The ratio of otolith size to fish size remained constant throughout and between the photoperiod, temperature, and feeding frequency experiments, regardless of the number or width of increments produced. Although otolith growth is isometric with respect to increase in fish length under these experimental regimes, otolith microstructure will differ in fish of the same size reared under different environmental conditions. An understanding of factors affecting otolith increment production is required before increment number and width can be used to assess growth rates.Key words: otolith, daily, growth increments, chinook salmon

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Molecular biodiversity under ocean warming: proteomics and fitness data provide clues for a better understanding of thermal tolerance in fish

10.7287/peerj.preprints.26669 ◽

2018 ◽

Author(s):

Diana Madeira ◽

José Eduardo Araújo ◽

Rui Vitorino ◽

Pedro Costa ◽

Catarina Vinagre ◽

...

Keyword(s):

Thermal Tolerance ◽

Elevated Temperatures ◽

Sparus Aurata ◽

Tricarboxylic Acid Cycle ◽

Expression Profiles ◽

Juvenile Fish ◽

Ocean Warming ◽

Cellular Stress Response ◽

Sea Bream ◽

Nursery Ground

Ocean warming is known to alter the performance of marine organisms albeit the proteome underpinnings of thermal tolerance are still largely unknown. Following a 1-month exposure to elevated temperatures we assessed the vulnerability of the proteome in the sea bream Sparus aurata to ocean warming. Fish were exposed to 18°C (control), 24°C (nursery ground) and 30 °C (heat wave year 2100). Survival was impaired after 28 days, mainly at 30°C although fishes’ condition was unaltered. Protein expression profiles (assessed at 14 and 21 days) were similar between fish exposed to 18 and 24ºC, differing substantially from fish exposed to 30ºC. Fish subjected to 24ºC showed enhanced glycolysis and decreased glycogenolysis mainly at 14 days of exposure. Fish subjected to 30ºC also showed enhanced glycolysis and up-regulated proteins related to gene expression, cellular stress response (CSR), and homeostasis. However, inflammatory processes were elicited at 21 days along with a down-regulation of the tricarboxylic acid cycle. Thus, juvenile fish acclimated to 24 but not to 30ºC as a result of increasing physiological constraints associated with metabolic scope available for performance at higher temperatures. Consequently, recruitment of sea breams may be in jeopardy with potential effects on population persistence and distribution.

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