ATCase activity, RNA:DNA ratio, gonad development stage, and egg production in the female copepod Calanus helgolandicus

1999 ◽  
Vol 135 (1) ◽  
pp. 1-10 ◽  
Author(s):  
I. C. Biegala ◽  
R. P. Harris ◽  
J. P. Bergeron
Keyword(s):  
Egg Production ◽  
Gonad Development ◽  
Development Stage ◽  
Rna:Dna Ratio ◽  
Atcase Activity ◽  
Calanus Helgolandicus

scholarly journals DEVELOPMENT STAGE, AGEING AND NATURAL MORTALITY OF ANCHOVY EGGS (Encrasicholina SPECIES) FROM BACAN

2017 ◽  
Vol 4 (2) ◽  
pp. 52
Author(s):  
Retno Andamari ◽  
Andriko N. Susanto ◽  
David A. Milton
Keyword(s):  
Egg Production ◽  
Production Method ◽  
Development Stage ◽  
Large Series ◽  
Natural Mortality

ln order to study the possible application of the Daily Egg Production Method (DEPM) for estimating anchovy (Encrasicholina spp.) biomass at Bacan. Maluku, we collected a large series of plankton samples.

scholarly journals The reproductive performance of the Red-Algae shrimp Leander paulensis (Ortmann, 1897) (Decapoda, Palaemonidae) and the effect of post-spawning female weight gain on weight-dependent parameters

2015 ◽  
Vol 63 (3) ◽  
pp. 207-216 ◽  
Author(s):  
Uwe Zimmermann ◽  
Fabrício Lopes Carvalho ◽  
Fernando L. Mantelatto
Keyword(s):  
Weight Gain ◽  
Egg Production ◽  
Reproductive Output ◽  
Coastal Region ◽  
Reproductive Traits ◽  
Development Stage ◽  
Female Size ◽  
Egg Volume ◽  
Average Fecundity ◽  
Female Weight

AbstractDecapod species have evolved with a variety of reproductive strategies. In this study reproductive features of the palaemonid shrimp Leander paulensiswere investigated. Individuals were collected in the coastal region of Ubatuba, São Paulo, Brazil. In all, 46 ovigerous females were examined in terms of the following reproductive traits: fecundity, reproductive output, brood loss and egg volume. Leander paulensis produces a large number of small eggs with an average fecundity of 635 ± 246 eggs. Egg volume increased significantly from early (0.034 ± 0.008 mm3) to late development stage (0.05 ± 0.012 mm3). The reproductive output did not correlate with female size. The weight of females bearing stage 2 eggs was significantly higher than that of females carrying stage 1 eggs. We assume that the reason for this weight gain is the recovery of female reserves that have been depleted for egg production. Moreover, we emphasize that this weight gain must be considered when evaluating weight-dependent variables such as reproductive output or brood loss in relation to female weight. Otherwise, an overestimation of these variables might lead to inaccurate results.

Feeding selectivity and egg production of Calanus helgolandicus in the English Channel

2000 ◽  
Vol 45 (1) ◽  
pp. 44-54 ◽  
Author(s):  
X. Irigoien ◽  
R. N. Head ◽  
R. P. Harris ◽  
D. Cummings ◽  
D. Harbour ◽  
...  
Keyword(s):  
Egg Production ◽  
English Channel ◽  
Feeding Selectivity ◽  
Calanus Helgolandicus

scholarly journals Histological and histochemical analysis of the gonadal development of males and females of Armases rubripes (Rathbun 1897) (Crustacea, Brachyura, Sesarmidae)

2009 ◽  
Vol 69 (1) ◽  
pp. 161-169 ◽  
Author(s):  
CM. Santos ◽  
GV. Lima ◽  
AA. Nascimento ◽  
A. Sales ◽  
LMY. Oshiro
Keyword(s):  
Gonad Development ◽  
Stage Iv ◽  
Cell Types ◽  
Gonadal Development ◽  
Development Stage ◽  
Seminiferous Tubules ◽  
Histochemical Analysis ◽  
Gradual Process ◽  
Histological Aspect ◽  
Different Cell Types

The objective of this study was to provide information on the histological characteristics of the gonads of male and female Armases rubripes crabs, and to try to establish a relationship between the microscopic and macroscopic stages previously identified. Thirty-six crabs were collected by hand between February 2003 and January 2004 in banks of Spartina alterniflora on Sahy Beach in Mangaratiba, Rio de Janeiro state, Brazil. The histological analysis of the ovaries of A. rubripes demonstrated a gradual process of development of the oocytes. According to their cellular characteristics, five types of cells were distinguished: oogonia, oocyte I, oocyte II, oocyte III and oocyte IV. The ovaries showed four stages during gonadal activity: stage I (rudimentary), stage II (developing or maturing), stage III (developed or mature) and stage IV (resting). The results of the histochemical analyses showed that the ovaries vary according to the gonad development stage. The histological aspect of one section of the male gonad was always the same in all of the seminiferous tubules, where the lumen of these tubules always contained spermatozoa and/or spermatids. It was not possible to characterize the three stages of gonad development in the males. This agrees with previous reports in the literature. However, in the females there was a relationship between the gonad stages distinguished macroscopically and the results obtained through the histological and histochemical analysis, due to the presence of different cell types, as well as the lysis process and reabsorption of the oocytes in spent females.

Regulation of mucosal lectins in the oyster Crassostrea virginica in response to food availability and environmental factors

2020 ◽  
Author(s):  
Simon Allam ◽  
Bassem Allam ◽  
Emmanuelle Pales Espinosa
Keyword(s):  
Gene Expression ◽  
Crassostrea Virginica ◽  
Gonad Development ◽  
Environmental Parameters ◽  
Development Stage ◽  
Gonad Maturation ◽  
Gene Expressions ◽  
Chlorophyll Contents ◽  
Lectin Gene ◽  
Food Particles

ABSTRACT Lectins are a large and diverse group of sugar-binding proteins involved in nonself recognition and cell-to-cell interactions. Suspension-feeding bivalves, such as the oyster Crassostrea virginica, are capable of using these molecules to bind cell surface carbohydrates of food particles, allowing particle capture and selection. The aim of this project was to assess whether the expression of mucosal lectins in C. virginica is constant or changes with the season, and to determine whether lectin expression is linked to environmental parameters and/or internal biological factors (gametogenesis). A total of 130 oysters were placed in submerged cages at a tidal estuary and monitored for changes in lectin gene expression over a 1-year period. In parallel, environmental parameters prevailing at the field site, including seawater physicochemical characteristics (temperature, salinity and dissolved oxygen), particulate organic matter and chlorophyll contents, were also monitored. Throughout the study, oysters were dissected and the gills were collected and used for the assessment of the expression of three different lectin genes (CvML, CvML3914 and CvML3912). Remaining tissues were processed for histology and the classification of the gonad development stage. Results showed that when food is abundant, such as during the spring bloom, lectin gene expressions are low, and inversely lectin levels increase with lower food levels. These findings suggest that oysters increase lectin expression to enhance the capture and ingestion of scarce food, while during spring, enough food is already being ingested and lectins are not needed. Furthermore, results showed that as the energy demands of oysters increase (gonad maturation), lectin gene expressions also increase to enhance selective ingestion of nutritious food particles. This study, therefore, demonstrates the seasonality of lectin gene expression in C. virginica, and suggests that lectin regulation is related to the reproduction process and abundance of high-quality food.

scholarly journals Gonad development and size at maturity of the male mud crab Scylla paramamosain (Forsskål, 1755) in a tropical mangrove swamp

2013 ◽  
Vol 1 (1) ◽  
pp. 7 ◽  
Author(s):  
Md. Sherazul Islam ◽  
Hisashi Kurokura
Keyword(s):  
Sexual Maturity ◽  
Carapace Width ◽  
Gonad Development ◽  
Reproductive Traits ◽  
Development Stage ◽  
Probit Analysis ◽  
Mature Stage ◽  
Scylla Paramamosain ◽  
Sample Population ◽  
Mud Crab

The reproductive traits and size at sexual maturity of the male mud crab Scylla paramamosain were investigated in Pak Phanang mangrove swamps, Thailand. Samples were taken seven times from the local middlemen mud crab traders during June 2006 to January 2008. Gonad development was determined based on histological appearance that was classified into three stages: 1) Immature (Spermatogonia), 2) Maturing (Spermatocytes) and 3) Mature (Spermatids and Spermatozoa). Among the sample population, the highest 72% was under gonad development stage I, whereas mature stage III was only 12%. The size at first maturity was estimated by the external allometric growth and histological observation of gonad. The size at which 50% of individuals attain sexual maturity was estimated by the two mathematical models such as probit analysis and logistic curve. The mean size at first sexual maturity and 50% maturation of male S. paramamosain were 96 mm and 109 mm internal carapace width (ICW) which revealed that 88% individuals were immature. The present result suggested that the minimum legal size of male S. paramamosain capture should be >110 mm ICW.

Seasonal variation on embryo production and brood loss in the Monaco shrimp Lysmata seticaudata (Decapoda: Hippolytidae)

2003 ◽  
Vol 83 (5) ◽  
pp. 959-962 ◽  
Author(s):  
R. Calado ◽  
L. Narciso
Keyword(s):  
Brood Size ◽  
Egg Production ◽  
Sex Change ◽  
Development Stage ◽  
Size Class ◽  
Reproductive Season ◽  
Embryonic Stage ◽  
Embryo Production ◽  
Major Period ◽  
Stage 1

The Monaco shrimp Lysmata seticaudata is a warm temperate species with strong potential for the marine aquarium industry and knowledge on embryo production and brood loss during incubation is essential for the establishment of proper maturation techniques. Average (±SD) brood size of small (total length (TL) 40–44 mm), medium (TL 48–52 mm) and large (TL 58–62 mm) simultaneous hermaphroditic (SH) phase were 753 (±215), 1351 (±163) and 1810 (±264) newly extruded embryos, respectively, in early reproductive season (ERS); and 745 (±258), 1314 (±191) and 1813 (±219), respectively, in late reproductive season (LRS). Senescence does not seem to occur in the Monaco shrimp, since during both ERS and LRS larger SH shrimp always presented a higher number of embryos and negative allometry was not recorded. No significant differences in brood size were recorded among broods at different embryonic stages of shrimp in the same size-class in both ERS and LRS. Brood losses recorded from embryonic Stage 1 to Stage 4 for small, medium and large shrimp were 14.3%, 11.3% and 8.9%, respectively, for ERS and 10.9%, 14.4% and 12.2%, respectively, for LRS. The mean embryo volume in the same development stage was not significantly different among the small, medium and large shrimp, and between ERS and LRS for shrimp of same size-class. For all shrimp size-classes during both ERS and LRS, mean embryo volume significantly increased from 108.5% to 127.9%, from first to last embryonic stage. The occurrence of sex change does not affect egg production since small females in ERS (before the major period of sex change) and LRS (after the major period of sex change) had similar brood sizes.

Influence of diatoms on copepod reproduction. I. Field and laboratory observations related to Calanus helgolandicus egg production

2006 ◽  
Vol 308 ◽  
pp. 129-142 ◽  
Author(s):  
SA Poulet ◽  
T Wichard ◽  
JB Ledoux ◽  
B Lebreton ◽  
J Marchetti ◽  
...  
Keyword(s):  
Egg Production ◽  
Calanus Helgolandicus

scholarly journals Temperature effects on Calanus helgolandicus (Copepoda: Calanoida) development time and egg production

2008 ◽  
Vol 31 (1) ◽  
pp. 31-44 ◽  
Author(s):  
D. Bonnet ◽  
R. P. Harris ◽  
L. Yebra ◽  
F. Guilhaumon ◽  
D. V. P. Conway ◽  
...  
Keyword(s):  
Temperature Effects ◽  
Egg Production ◽  
Development Time ◽  
Calanus Helgolandicus
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