Mean Diameter Of Eggs Research Articles

Artificial Reproduction of Zebrafish Dania rerio under Controlled Laboratory Condition

The objective of this study was to describe a standard universally accepted artificial culture protocol for zebrafish. Also, developmental stages of embryogenesis were also described. Because Zebrafish are considered as a model organism and are widely used in biomedical research to study human genes and human diseases. Despite this, the artificial reproduction of zebrafish is poorly described, and there is not any standard universally accepted artificial culture protocol. To satisfy the scientist working in the biomedical area, a standard culture method of zebrafish under controlled laboratory conditions must be developed.
 The present study was conducted at the Aquaria Research unit of Marine Sciences and Technology Faculty of Iskenderun Technical University, Iskenderun Turkey, from March 2018 to October 2018.
 Spawn traps and gravels are not used for spawning of broodstock. Female and male broodstock were selected from our previously cultured stock, based on their swollen abdomens. Mean body lengths for female and male were 3.34±0.40, 2.97±0.3 cm and the mean weights were 0.38±0.14, 0.25±0.27 g, respectively. First eggs were squeezed from the ovaries then milt was taken from the testes onto the eggs. Fertilisation was done artificially by the dry method. The eggs hatch within 4-5 days at 28±1°C. The mean diameter of eggs and fecundity were measured using a micrometre attached to a microscope. During the experimental studies, the water quality parameters were also maintained at optimum.
 In the present study, temperature and pH were maintained at 28±1°C, and 7.28 respectively and which were the best for reproduction of zebrafish. Fecundity differed widely between individuals, and the number of eggs ranged from 7 to 110. The average diameter of the eggs ranged from 405± 0,001 to 570 ± 0,001 µm. Mainly seven developmental stages of embryogenesis were described; the zygote, cleavage, blastula, gastrula, segmentation, pharyngula and hatching stages.
 The results of the present study suggest that with the right artificial culture conditions and proper manual stripping, the required number of eggs and embryos for biomedical research can be easily obtained.

Intra-Specific Variation in Pseudepidalea viridis in Fars Province, Iran: Life History and Developmental Patterns

This study describes the influences of variations in life history traits and developmental patterns of Pseudepidalea viridis. The causes of this variation were investigated by comparing observed patterns of inter-populational differences. The aim of the study was to investigate whether embryos and larvae from different populations of P. viridis show the same pattern of development when they are reared in the same conditions in the laboratory. Egg masses of P. viridis were collected from four sites in Fars Province, Iran and reared in the same conditions. Samples from most of the developmental stages were fixed and clutch parameters were measured at early developmental stages. Morphological characters in embryos and larvae including egg diameter and growing size at different stages, as well as external gill, cement gland and mouth part structures were examined with light and scanning electron microscopy. Statistical analysis showed that the mean diameter of eggs and jelly coats were significantly different (P < 0.05) from each other in all four populations. In addition, variation among sites in developmental stage at age of embryos and larvae were found. The results also showed type B cement gland developmental pattern and significant differences in external gill filaments amongst the populations. The dental formula was 2 (2)/3 and revealed no differences in the number and situation of dental rows among the populations. Our data suggest that local adaptation may be responsible for life history and morphometric and morphological variations among eggs, embryos and larvae of P. viridis.

Biologie De La Reproduction Du Sciaenidae Pseudotolithus Elongatus Dans La Lagune Ebrie (Cote d’Ivoire)

The study of reproduction of Pseudotolithus elongatus in the Ebrie lagoon was investigated between July 2013 and June 2015 on a whole of individuals of 550 specimens. the total length ranges from 14.5 to 42.7 cm. The monthly evolution of the gonado-somatic index (GSI), the liver-somatic index (LSI), the condition factor (K), the Sex-ratio, the fecundity, the diameter of eggs revealed that this species spawns throughout the year but the main breeding period was in raining season. Sex-ratio observed was in favour of females (1: 1. 14; X2 = 2.26; p &gt; 0.05). The percentage of mature specimens by sexes was calculated for each size class. Total length at first maturity was 21.06 cm for females and 20.21cm for males. The ripe ovaries contained 39883-814757 eggs. The relative fecundity was 216-1979 eggs per g of body weight of females. And the mean diameter of eggs is 336 ±138 microns.

Growth and reproductive properties of Tench,Tinca tincaLinnaeus, 1758 in Trasimeno Lake (Umbria, Italy)

Growth and some reproductive properties of native Tinca tinca Linnaeus, 1758 from Trasimeno Lake were investigated during 2009 and 2010. The total sample of fish (510) was composed by 126 males, 221 females and 163 immature specimens. Total length (TL ± 0.1 cm) and weight (W ± 0.1 g) were recorded; age estimation was based on scalimetry and sex was determined by microscopic observation of the gonads. Age composition varied from 1+ to 11+ . The TL -W relationship was log 10 W = −2.235 + 3.248log 10 TL . Previous growth was determined with back-calculation from scale measurements using the Fraser-Lee method. Theoretical length growth was estimated with von Bertalanffy’s model. Analysis of the gonadosomatic index (GSI) suggests that the reproductive period of the population took place from May to July. Sexual maturation occurred in both sexes at the second year of life. The mean diameter of eggs was 0.075 mm. The mean number of eggs produced by each female was 233 930 and increased with the size of the specimens. Though it is one of the most widespread and interested species in fishing in Italian waters, tench has not been widely studied; this research deepens some biological characteristics of this species that is strongly shrinking in Italy.

Effects of temperature on biological and biochemical indicators of the life‐history strategy of bullheadCottus gobio

The biological and biochemical effects of temperature on life-history strategy of female bullhead Cottus gobio were investigated. Fish from two populations (Bez Basin, south-east France) experiencing contrasted thermal environments (i.e. more or less stable) were reared during 4 months at three distinct temperatures (7, 9 or 12 degrees C). Both somatic (soma fresh mass and muscle triglyceride content) and reproductive (gonad fresh mass, fecundity, mean diameter of eggs and gonad triglyceride content) indicators were examined. Mixed models indicated that an increasing temperature had significant negative effects on all life-history indicators except for soma fresh mass. Differences in life-history strategy with regard to muscle and gonad triglyceride contents, however, suggest that populations experiencing more variable thermal environments may be better adapted than others to cope with an increasing temperature. These findings may have important implications for C. gobio populations, within the context of climate warming.

Spawning and parental care in Hoplias malabaricus (Teleostei, Characiformes, Erythrinidae) in the Southern Pantanal, Brazil

Herein we describe spawning and egg guarding in the erythrinid fish Hoplias malabaricus observed in the southern Pantanal (19 degrees 34' S and 57 degrees 00' W), state of Mato Grosso do Sul, Brazil. Nests were depressions built on sandy soil in flooded areas, and contained a mean of 8,197 +/- 2,204 eggs (N = 4); the mean diameter of eggs was 1.44 +/- 0.09 mm (N = 400). Among 11 nests observed, eight were guarded by males and three by the pair. One male remained in the nest for six days, and two pairs remained guarding the eggs for at least three days before being captured. Females (N = 2) captured in the nest contained oocytes in their ovaries. Our observations suggest that male parental care is the normal form of parental care in H. malabaricus, but biparental care also seems to occur.

THE FECUNDITY, TIME OF EGG DEVELOPMENT AND JUVENILE PRODUCTION IN SPINY-CHEEK CRAYFISH (ORCONECTES LIMOSUS) UNDER CONTROLLED CONDITIONS

We comprehensively describe the fecundity and time of embryonic development of the spiny-cheek crayfish (Orconectes limosus). Linear relationships between female size and ovarian fecundity, pleopodal fecundity, and production of juveniles at the 3rd stage, were confirmed. The ovarian fecundity was evaluated for the smallest as well as largest females in the sampled population (43-93 mm of body length); the number of oocytes (eggs) ranged widely, between 46 and 505. No significant difference was found between the ovarian and pleopodal fecundity observed just after egg laying. The value of the female gonadosomatic index just before laying was 4.2 ± 1.8% (0.8-7.7%). The mean diameter of eggs on female pleopods was 1.8 ± 0.2 mm (1.45-2.15 mm). A statistically significant difference was found between the numbers of eggs carried on individual pairs of pleopods. Mean time from laying to hatching was 46 ± 3.8 days (37-56 days), i.e. 647 ± 39.9 CTU (Celsius Temperature Units = degrees Celsius × days). Mean production of juveniles at the 3rd stage was found to be 135.7 ± 67.24 (15-243) juveniles. The early sexual maturation and also high number of juveniles at the 3rd stage per female gives this species a good predisposition for quick establishment in new localities.

Aspectos da reprodução do caranguejo guaiamum, Cardisoma guanhumi Latreille (Crustácea, Decapoda, Gecarcinidae) da Baía de Sepetiba, Rio de Janeiro, Brasil

The objective of this work is to get knowledge about the guaiamum crabs reproduction. Two hundred and twenty four crabs were caught from August'96 to July'97. Their sex carapace color and morphometric data were obtained. The stages of gonadal development were macroscopically determined and the eggs diameter was measured. Three colors patters for the carapace for males, and four patters for females. Five stages of gonadal development were observed in female crabs, and two stages were observed for males. The first sexual maturity was estimated 53,0 mm carapace width for the females and 52,0 mm for the males. The ovigerous females occurred from March to May. The individual fecundity varied from 103.300 to 366.400 eggs. The eggs mean diameter was 0,39 mm.

Some aspects of the biology of a cyprinid, Aspius vorax Heckel

Scales were used for the determination of age with back‐calculation of length. The oldest fish was VII + years old. Back‐calculation did not exhibit Lee's phenomenon. The most rapid growth occurred in summer at water temperatures over 25°C. The growth in weight was c. 331 g year‐1 after IV vears of life. Growth was well described by von Bertalanffy equation : ll ‐ 91·0 [l=0·122(l0·25)] The length‐weight relationship followed the cube law (b = 3·0601) Kn ranged from 0·74 to 1·18 with a mean value of 1·0. Spawning occurred in January, fecundity was 74 509 with a mean of 1157 eggs ‐1 body weight. Mean diameter of eggs was 1071 (pm). A developed ovary had ova of two sizes, immature oocytes and mature ova. The fish is a carnivorous feeder.

Age, Growth, and Fecundity of the Rosyside Dace, Clinostomus funduloides Girard

Information on growth rate, age composition, and fecundity of rosyside dace was obtained from a sample of 212 fish collected from April to August 1970 from the North Branch of Jennings Run, Potomac River drainage. Total lengths ranged from 46 to 94 mm and average weights ranged from 1.4 g (40–49 mm length class) to 10.4 g (90–99 mm length class). Ages of rosyside dace included age groups I to IV. Sexual maturity was attained at about 53 mm and age I for both sexes. The spawning season lasted from early May until late June. The mean diameter of eggs during the spawning season ranged from 1.05 mm in May to 1.20 mm in June. Fecundity ranged from 139 (56–59 mm length class) to 802 (90–95 mm length class). There was a high correlation between fecundity and length and weight of dace, but a low correlation between fecundity and age and weight of ovaries.

Maturity and Fecundity of Walleyes from the Eastern and Western Basins of Lake Erie

Of 2427 walleyes (Stizostedion vitreum vitreum (Mitchill)) examined from Lake Erie in 1964–66, no females were mature at ages below III and all were mature at age V. All male walleyes from the eastern basin were mature at age II, and those from the western basin at age III. Females from the western basin matured at a shorter length and a younger age than those from the eastern basin. Males from the western basin, on the other hand, matured at a longer length and greater age than those from the eastern basin.Egg production, which was estimated for 60 walleyes from the eastern basin and 78 from the western basin, ranged from 48,000 to 614,000. The number of eggs increased rapidly with increase in total length, but the relation between fecundity and weight was almost linear. Walleyes from the western basin were much more fecund for any given length, weight, or age than those from the eastern basin. Weight was the most accurate indicator of fecundity. The mean diameter of eggs from 32 ripe walleyes was 1.72 mm. Little relation existed between egg diameter and length or age of fish.