Egg Diameter Research Articles

Fecundity and egg diameter of endemic fish (Telmatherina bonti Weber and De Beaufort, 1922) from Towuti Lake, South Sulawesi, Indonesia

Lake Towuti are an ancient lake and an oligotrophic lake. The lake is a habitat for endemic fish species such as bonti-boni fish (Telamatherina bonti). These fish are of important economic value. The purpose of this study was to analyze fecundity and egg diameter of T. bonti in Towuti Lake. The research was conducted at Towuti Lake from January to December 2019. The Samples were collected using seser and it was separated between male and female based on morphological characteristics of the body and gonads. Gonads were preserved in fomaldehyde 4%. The absolute fecundity ranged from 442-1435 eggs. The relationship of fecundity with body weight was greater than the relationship of fecundity with total length. The diameter of the eggs inside the gonads varies. The type of T. bonti spawning was categoried of partial spawner.

Comparative Egg Production, Quality and Hatchability in Three Chicken Genotypes under Humid Tropical Conditions

Comparative study on egg production and hatchability characteristics in Nigerian local (NL; n=24), FUNAAB-α (F-α; n=24) and Transylvanian naked neck (TNN; n=24) chickens aged 25 weeks old was carried out for 4 weeks. Three hundred and sixty hatchable eggs each were used for quality characteristics determination and for incubation. F-α had significantly (P<0.001) higher egg production (90.3%) than TNN (76.9%) while TNN was higher than NL (58.3%). Egg weight (EWT), length, width and surface area, albumen height, weight, percentage and index, shell weight, color and internal quality unit (IQU) were significantly (P<0.001) affected by genotype. These followed the pattern: NL<F-α<TNN. F-α and TNN had significantly (P<0.001) higher values than NL in egg shape index, yolk weight, height and diameter. Yolk colour index was significantly (P<0.01) higher in TNN than in F-α. Yolk percentage and yolk-albumen ratio followed the pattern: NL>F-α>TNN. NL had (P<0.001) thicker and higher shell percentage (SP) than F-α and TNN. Higher Haugh unit (HU) was recorded in TNN than in NL and F-α. Fertility was significantly (P<0.05) higher in F-α than in TNN. Hatchability was not (P>0.05) affected by genotype. Chick weight and chick: egg ratio were significantly (P<0.001) by genotype. TNN had higher chick weight and yield than F-α and NL chicks. In conclusion, F-α laid more eggs than others, exhibited higher fertility with longer chicks at hatch. TNN is superior in EWT, HU, IQU and chick yield. NL had higher SP than others.
 Keywords: Egg production, Egg quality, FUNAAB alpha chicken, Hatchability, Transylvanian naked neck chicken.

Seasonality of Gamete Production of Cyclonaias Species in Central Texas

Reproductive traits, which can impact population health, are important life-history characteristics for freshwater mussels. Little research has been done on the reproductive ecology of mussels, and crucial information is missing for many threatened and endangered species, especially in Texas. The objective of this study was to examine gamete production, parasitic infection rates, and sex ratios of two freshwater mussel species (Cyclonaias petrina and Cyclonaias pustulosa) in the Llano and San Saba rivers in central Texas. Gamete densities and egg diameters of C. petrina in the Llano River varied seasonally, with peak gamete densities occurring in December and February 2017 and being significantly lower from June through September 2017, while the relative abundance of the largest size classes of eggs was highest in February 2018. Few to no differences were detected in gamete production and egg diameter sizes for C. petrina between rivers. Cyclonaias pustulosa had significantly higher sperm densities and smaller egg diameters compared to C. petrina but exhibited similar egg densities in the San Saba River. There were no significant differences in gamete densities between rivers and no significant correlations between shell length and gamete density. Infection rates of parasitic trematodes varied from <1% to 14%, with the highest infection rates occurring in C. petrina in the San Saba River. Sex ratio of C. petrina was slightly skewed toward females in the Llano River and toward males in the San Saba River, with C. pustulosa having a 1:1 sex ratio in the San Saba River. The high percentage of samples without gametes suggests that the reproductive outputs of Cyclonaias appear to be more limited in the San Saba River due to several potential stressors. Further research will need to investigate the relative importance of the various stressors that affect the reproductive ecology of mussels and their persistence.

Effect of dietary astaxanthin on reproductive performance, egg quality and larvae of clowfish &lt;i&gt;Amphiprion ocellaris&lt;/i&gt; (Cuvier, 1830)

This study was designed to evaluate the effects of astaxanthin in broodfish diets on reproductive performance, egg quality and larvae quality parameters of clownfish (Amphirion ocellaris). Five treatments were tested with 5 levels of astaxanthin (Carophyll Pink 10% CWS) of 0, 50, 100, 150 and 200 mg/kg added to the feed. Each treatment was repeated in triplicate and the supplemental feeding trials were arranged for 13 months. The results showed that there were significant differences in hatching rate of egg, malformed rate and survival rate of larvae in 3 days post-hatch (p&lt;0.05) among the feeding trials of astaxanthin supplements. The highest hatching rate of egg and survival rate and the lowest malformed rate of larvae were observed in the treatment that was supplemented with astaxanthin 150 mg/kg feed, respectively 92.14 %; 93.57 % and 0.55 %. However, the astaxanthin supplementary diets did not affect the re-maturation and spawning period, spawning frequency, fecundity, egg diameter and larval size of nemo fish among the treatments. The results also suggested that astaxanthin requirement for clownfish broodstock to improve reproductive performance was 150 mg/kg feed.

Reproductive biology of hampala barb (Hampala macrolepidota Kuhl & Van Hasselt 1823) in Ranau Lake, Indonesia

One of the economically valuable consumption fish in Ranau Lake is the hampala barb (Hampala macrolepidota). Hampala barb is the top predator in Ranau Lake. The fish population is still quite a lot, but it is starting to decline. This study aimed to determine the reproductive biology of hampala barb in Ranau Lake. Ranau Lake is located in South Sumatra Province and Lampung Province, Indonesia. The research was conducted by the inventory survey method and laboratory analysis. Fish samples were obtained from fisher’s catch, where the fish were caught using gill nets with varying mesh sizes and harpoon. The fish were measured for length body and total weight. Then surgery was performed to determine their reproductive biological characteristics (sex, size of first gonad maturity, gonad maturity stage, Gonad Somatic Index, fecundity, and egg diameter). The results showed that the hampala barb in Ranau Lake laid the eggs throughout the year with a sex ratio of 1: 1, the size of the first stage of gonad maturity of male and female were 15.38 cm and 19.21 cm, fecundity between 17,406-63,793 eggs, and egg diameter between 0.8-1.9 mm. This reproductive biology information can be used for the management of hampala barb in Ranau Lake.

The development of adapted marmorated medaka Oryzias marmoratus (Aurich, 1935) at ex-situ habitat

Marmorated Medaka (Oryzias marmoratus) is a small endemic fish species of Malili Lakes, South Sulawesi, Indonesia. The fish is a valuable commodity as an ornamental fish. However, their population in wild is threatened with extinction and has been categorized as vulnerable by IUCN. An effort to conserve O. marmoratus by ex-situ breeding is necessary for its sustainability. Research Center for Limnology-LIPI has succeeded to take the fish from Lake Towuti and adapted them in an ex-situ habitat (laboratory) (2017–2018). Research on the development to adapt O. marmoratus outside their natural habitat has been conducted in 2019-2020. The sex ratio of male: female was 1:2 (1:2.223±0.638). During mass spawning, the fish was able to reproduce seven times in 37 days which the dark moon phase. Egg diameter (mm) was 1.193±0.017. Reproduction viability was very good. Fertilization and hatching rates were 100% and 98.149±3.347%, respectively. Length of Incubation Period (LIP) (days) was 7.286±1.329, and the larva size (mm) was 3.3±0.483. Survival Rate on seven days (SR7) was 97.02112±5.510 % with larva size of 5.5±0.707. Juvenile size (mm) at 16 weeks was 33.6±5.661 (26–42). Oryzias marmoratus can be developed in ex-situ habitats and still needs further research.

Reproductive and larval performance of artificially spawned javaen barb Systomus orphoides from two populations

Indonesian freshwaters are rich in fish biodiversity, one of them is javaen barb. In terms of domestication, it is important to ensure the fish breeding and larval rearing in ex-situ environment. Therefore, studies on artificial spawning are needed to strengthen the information about reproduction of javaen barb in ex-situ environment for domestication and aquaculture purposes. This study aimed to evaluate the reproductive and larval performance in artificially spawned javaen barb within two populations. Broodfish were obtained from West Java (Tasikmalaya and Cianjur population), kept on the fish nets (2×2×1 m) inside the large ponds for two months of adaptation. Broodfish were attached by RFID chips and periodically observed their size and gonad maturity level. Ripen broodfish were artificially spawned. Several reproductive parameters were observed during the experiment, such as egg diameter, fecundity, fertilization rate (FR), hatching rate (HR), and hatching time. Moreover, larval performance was also observed. The results showed that javaen barb successfully spawned with 11 hours of latentcy period. Javaen barb from Tasikmalaya population had a significantly higher fecundity than that of the Cianjur population. Meanwhile, other parameters observed in relation with reproductive and larval performance were not significantly different.

Ecobiology of horseshoe crab in Brebes, Northern Coast of Java: Preliminary study

Horseshoe crabs are known as living fossils and three species are found in Indonesia where all of them are being protected. The research aimed to assess ecology, species composition, and biological aspects in Brebes estuary. The research was conducted in August and October 2017 in Brebes Estuary. Samples were caught using local fishermen and experimental gears. Parameters of water quality were observed insitu and substrate was analyzed in the laboratory. The horseshoe crabs were measured morphologically, their stomach and eggs were taken to be analyzed in the laboratory. Total specimens of horseshoe crabs were 33 individuals (Tachypleusgigas=8; Carsinoscorpius rotundicauda=25). T. gigas has 16.3-22.6 cm of prosomal width and 216.1-717.0 gram of weight. C. rotundicauda has 11.2-14.5 cm of prosomal width and 96.0-275.5 gram of weight. Stations with a muddy sand substrate (silt >50%) have the highest number of captured horseshoe crabs. Food habits of T. gigas are macrophytes and detritus while C. rotundicauda are macrophytes, molluscs, annelids, and coral. Niche breadth of C. rotundicauda were wider than T. gigas. High niche overlap value between T. gigas and C. rotundicauda indicates high competition in utilizing food sources. The fecundity of C. rotundicauda was higher than T. gigas but the egg diameter of C. rotundicauda smaller than T. gigas.

Biology of reproduction in Otolithoides pama (Hamilton, 1822) in Hooghly-Matlah Estuary of West Bengal, India

Pama croaker, Otolithoides pama (Hamilton, 1822) is one of the commercially important demersal fish of Hooghly-Matlah estuarine system, West Bengal, India. Reproductive biology of 618 samples of O. pama (Hamilton, 1822) collected from the Hooghly-Matlah estuarine system of West Bengal, India for a period of 18 months (November 2016 to April 2018) was investigated. The total length (TL), body weight (BW) and ovary weight (OW) of the samples varied from 100-384 mm, 7.29-470.71 g and 1.5-29.49 g, respectively. The sex distribution was 1 male for 1.07 female and the ratio did not differ statistically. The length at first maturity (Lm) was recorded as 183 mm for males and 196 mm for females. The reproductive activity was found throughout the year with three peak spawning season with high gonadosomatic index (GSI) values, i. e., during February-March, June and September-November. The absolute fecundity ranged from 4652 to 170688 eggs (24950±32441.2) and relative fecundity ranged from 96 to 808 eggs per g body weight (382±176.83). Fecundity exhibited a relatively higher significant correlation with ovary weight (r = 0.973, p&lt;0.01), compared to total length, total weight and ovary length. Egg diameter frequency showed polymodal distribution, indicating that the species is a batch or asynchronous spawner.

Blue Crab Spawning and Recruitment in Two Gulf Coast and Two Atlantic Estuaries in Florida

AbstractThe present study aimed to investigate the life history traits of blue crabs Callinectes sapidus found in four estuarine systems—two on the Gulf coast of Florida (St. Andrews Bay and Suwannee Sound) and two on the Atlantic coast (St. Johns and Halifax rivers). Females in St. Andrews Bay, Suwannee Sound, the St. Johns River, and the Halifax River reached maturity at a carapace width (measured from lateral spine tip to lateral spine tip) of 116.5, 121.9, 129.5, and 123.7 mm, respectively. At both Gulf coast locations, year‐round spawning was not observed; peak spawning occurred in early to late spring, and in St. Andrews Bay there was an additional fall spawning event. On the Atlantic coast, spawning females were collected almost year round, with the greatest abundance in winter through spring and an additional peak in late summer. Potential fecundity on both coasts was directly correlated with body size and was greatest at the beginning of each reproductive season. Egg diameter from crabs on both coasts was independent of female size and was influenced by month, with the largest egg diameters observed in the earlier months of the year. Overall, there was an inverse relationship between potential fecundity and egg diameter. Mean potential fecundity for females sampled in St. Andrews Bay, the Halifax River, and the St. Johns River was 1.8, 2.1, and 2.2 million eggs, respectively. This demonstrates that seasonality is important for blue crab reproductive output and for the timing of juvenile and fishery recruitment.

Comparative morphology and morphometry of the micropyle of two Korean rice-fishes, Oryzias latipes and Oryzias sinensis (Pisces, Adrianichthyidae)

The morphology and morphometry of the micropyle of two Korean rice fishes, Oryzias latipes and O. sinensis, were investigated by light microscopy and scanning electron microscopy. Obtained from adult gravid females during the spawning season, the full-grown eggs of each species have a single micropyle at the animal pole. For the two species, the micropyles are similar in appearance, but there exist some differences in detail. The egg is larger in O. latipes than in O. sinensis (1,123.3-1,465.5 µm vs. 823.1-1,152.1 µm in diameter), and the outer diameter of a single micropyle for O. latipes is nearly two times larger than that of O. sinensis (18.5-22.4 µm vs. 10.0-12.5 µm). The micropylar diameter to egg diameter ratio (1.6 ± 0.1% vs. 1.0 ± 0.1%) is also larger in O. latipes than O. sinensis. In regard to micropyle structure, the two showed distinguishing characteristics: O. latipes has a funnel-shaped micropyle consisting of two regions, an outer gradual pit and an inner narrow canal, while O. sinensis has a conical-shaped micropyle having only a deep narrow canal. Consequently, these differences in micropylar structure between the two Korean rice-fishes may be considered as a useful taxonomic characteristic in closely related taxa and seem to be structural adaptations to shape and control entry velocity of spermatozoa into the micropyle.

Fatty acid composition and spawning quality in wild and captive broodstock of Pacific red snapper Lutjanus peru

The Pacific red snapper (Lutjanus peru) is very popular fishery that reaches high prices in the market that is distributed in tropical and subtropical climates. Most studies in fatty acid requirements for larval production are done in temperate species; in general, warm-water fish are given the same levels of DHA and EPA than cold-water fish, which increases considerably the costs of production, without apparent benefit. We analyzed spawns during lecithotrophic development, with emphasis on fatty acids, of L. peru. Three origins were compared, Wild spawns, used as the standard of better-quality larvae, Laboratory and Pond, each with some differences in the inductions of maturation and broodstock diet: Lab and Pond broodstock were fed sardines and squids and DHA-rich oil capsules were added once a week. A total of 87 spawns were sampled throughout three years of sampling. Egg and oil globule diameters before fertilization, in 1-h embryo (E) and before hatching (LE); larval total length and oil globule diameter at hatching (LH), and after 24 (L24h) and 48 h (L48h) were measured. Hatching and survival percentages were measured in triplicate for each spawn. Hatching were significantly higher from Pond spawns (75.7%) compared to Wild (60.8%). Survival at L48 hours was not significantly different among origins. Wild spawns had significantly more carbohydrates, but less phospholipids during development, compared to Lab and Pond spawns. ARA, EPA and DHA concentrations decreased in total lipids and triglycerides, but in Lab spawns they were accumulated in phospholipids. There was a more variable fatty acid composition in Pond spawns compared to Lab spawns, a result of more diversified diet in ponds. Viable eggs had two-fold higher proportion of ARA compared to non-viable eggs. A principal factor analysis revealed three positive associations between 1) female weight, egg oil globule diameter, and EPA:ARA in egg PL; 2) hatching, LH length, and DHA:ARA in egg PL; 3) L48h survival, TG and PL content in eggs. According to our results, subtropical L. peru needs less DHA and more ARA and monounsaturated fatty acids in their diet, compared to temperate marine fish.

Egg diameter of female silver rasbora (Rasbora argyrotaenia) at different gonadal maturity stage

As a new aquaculture species, silver rasbora (Rasbora argyrotaenia) has a high demand for consumption and ornamental fish in Indonesia and its surroundings. The aim of this study was to measured egg diameter in female silver rasbora at different maturity stages. This study was conducted in February 2020 at instrument laboratory Universitas Airlangga, Banyuwangi Campus, Indonesia. A total of 16 females of silver rasbora with a weight of 1.73±0.08 g and length of 5.39±0.13 cm was obtained aquaculture installation of Universitas Airlangga, Banyuwangi Campus, Indonesia. Based on the result, the egg diameters were observed in II, III, and IV maturity stage in the amount of 17.96 ± 1.88 µm, 47.15 ± 10.07 µm, and 83.02 ± 4.40 µm. This information will reach our knowing of the maturation cycle of silver rasbora and also improve artificial techniques of culturing fish for commercial purposes and conservation stocking.

Ebu Kefalinin Üreme Biyolojisi, Planiliza abu (Heckel, 1843), Karun Nehri, Güneybatı İran

Some aspects of the reproductive biology of Planiliza abu (Mugilidae) were investigated by collecting of 428 specimens caught with trawl by local fishermen from Karun River, Ahwaz, from November 2016 to September 2017. Total length for males ranged between 10-17.1 (13.6±1.26 SD) cm and for females, between 10.5-17.3 (13.44±1.35) cm. The age range of fish in both sexes was between 0+-7+ years and the most abundant age group was the 4+. Sex ratio in the studied fish was equal (P&amp;gt;0.05). The mean egg diameter was significantly different (P&amp;lt;0.05) in different months and the individual size ranged between 0.12 and 0.57 mm. The absolute fecundity ranged from 3600 to 48600 eggs and the relative fecundity from 120 to 900 eggs per 1 g of body weight. The highest hepatosomatic index in females was in February during yolk vitellogenesis (1.89). Based on gonadosomatic index, egg diameter and monthly distribution of ovarian maturation stages, the spawning season of this fish is long, but peaks in February (GSI 12.35) and March (GSI 12.18). This species appears to have a group synchrony reproductive pattern.

Sex Ratio, Fecundity and Morphometry of the Eggs of Freshwater Prawn Macrobrachium Americanum (Bate, 1868) in the Petatlán River, Sinaloa, Mexico

Abstract Macrobrachium americanum has a high commercial value with good fishing and cultivation possibilities in Mexico. Currently there is little information on reproductive aspects so the present work analyzed the sex ratio, fecundity and morphometry of the eggs of M. americanum in the Petatlán River, Sinaloa, Mexico. A total of 31 ovigerous females were captured. The sex ratio was 0.39 F: 1 M. The partial fecundity (Pf) varied from 34, 554 to 342, 372 eggs (128, 246 ± 12, 306 eggs, average Pf). The relationships between body and length-fecundity (R2= 0.5546), cephalothorax and length-fecundity (R2= 0.4995) were adjusted to a linear model, and the total weight-fecundity to a potential model (R2= 0.5013). The average relative fecundity was 37, 132 ± 5, 162 eggs/g. A total of 7 stages of embryonic development were observed. In the first stages, the egg presents a spherical form and in the latter an ovoid shape. Maximum egg diameter values are presented in stages VII, VI and VIII. Stage II provided the largest number of eggs (1, 013, 073 eggs). It is essential to optimize the exploitation of the population of M. americanum present in the Petatlán River through the creation of scientific bases for the sustainability of the fishery.

Comparative Test Of Ovaprim, Spawnprim, And Hcg In The Process Of Spawning Of Pangasianodon Hypopthalmus, Sauvage 1987.

Pangasianodon hypophthalmus is a type of freshwater fish that has potential and has economic value. Its production target which increases every year causes farmers to spawn with the help of hormonal stimulation. The aimed of this research was to test and find out the results of the use of three different hormones namely Ovaprim, Spawnprim, and HCG in P. hypopthalmus spawning. This research was conducted in January 2020 at the Trimurjo Fish Seed Center, Central Lampung. This research used a randomized complete design method with the 3 treatments, P1 (Ovaprim 0,5 ml / kg), P2 (Spawnprim 0,5 ml / kg), P3 (HCG 500 IU / kg) and 3 replications. The results of this research indicate a significant difference (p &lt;0,05) in the relative fecundity parameters, fertilization rate, and hatching rate, but not significantly different in the parameters of latensi periode and diameter of eggs. In P1, Ovaprim hormone injections provide better reproductive performance compared to Spawnprim and HCG injections.

Influence of maternal weight, age, larval feeding and their interactions on the hatchery outcomes of an Indian major carp (Labeo rohita, Hamilton 1822)

Broodstocks’ size (weight or length), age and larval feeding are crucial in the production of good quality gametes and larvae in any fish. Therefore, this study was conducted with two experiments to understand 1) effects of maternal weight and age, and 2) effects of maternal weight, age, larval feeding and their interactions on egg and larval traits using the Indian major carp (Labeo rohita). In both experiments, females were divided into two size groups based on their body weights (‘large’ and ‘small’) to obtain eggs and larvae. In experiment-1, parameters of egg quality such as egg weight, egg number, egg diameter, egg area and hatching rate were assessed, and larvae were reared up to two weeks with optimum feeds to evaluate their traits such as deformation rate, survival rate, total length and body area. In experiment-2, only the three-day old larvae were randomly assigned into two feeding regimes (‘everyday’ and ‘every other day’) up to two weeks to assess their fitness. The results revealed that egg weight, hatching rate, larval total length, body area increased significantly (P <0.05) and hatchling deformation rate decreased significantly (P <0.05) with the increase of female age, whereas only egg weight was linearly related to female weight (R2 = 0.47, P <0.05) in experiment-1. The experiment-2 showed that everyday fed larvae had significantly (P <0.05) higher survival rate, total length and body area than those fed every other day. The dietary treatment found no significant effects of maternal age, weight and their interactions with larval feeding. Thus, the study showed that maternal body weight, age and larval feeding may influence some traits of egg and larval fitness. The overall findings suggest that maternal weight, age and regular larval feeding must be considered to produce good quality of gametes and larvae for sustainable production of this species.

Wild Salmo trutta labrax from the Bıçkı Stream in the Marmara Region: Gamete Quality and First Reproduction Under Aquaculture Conditions

In this study, the quality and reproductive success of wild Black Sea Trout (Salmo trutta labrax) were investigated. In total 32 wild trout (27.3±13.6 g and 13.9±2.3 cm) from the Bıçkı Stream in Kocaeli Province in the Marmara Region were kept in circular fiberglass outdoor flow-through tanks (1.5m ø) at the mean water temperature of 11.8±4.5 °C. In November 2016, when the water temperature was 8.4 °C, the first spawning of wild trout occurred. Sperm volume (ml), Motility (%) and VCL (µm/ sec) values were determined to be 7.5±2.5, 70.42±0.83 and 70.35±3.98, respectively. The weight (g), total fecundity and egg diameter (mm) values of female fish were listed to be 513.75±78, 1.171±171, and 3.84±0.02, respectively. In the experiment, 5.859 wild Black sea trout eggs were fertilized. The eyed-egg stage occurred 24 days (288 day-degree) post fertilization and the survival rate from fertilization to the eyed-stage was 28%. Wild Black Sea trout larvae from P1 (Paternal Generation) hatched 48 days after fertilization with the hatching rate of 7%.

Effects of skip a day (SAD) feeding regime during rearing on the subsequent laying performance of Black Harco hens

One hundred and fifty (150) black harco pullets were used in a study designed to investigate the effects of Skip A Day (SAD) feeding regimen during rearing on their laying performance. Pullets from a healthy stock were randomly allocated into five experimental groups at 12 weeks of age. Birds in group I were fed ad libitum daily, while those in groups 2, 3, 4 and 5 were subjected to SAD feeding regimen for 2,4,6 and 8 weeks, respectively. Hens in all groups were thereafter fed ad libitum during a 30-week laying period. Birds in all treatment groups had unrestricted access to water before, during and after the period of feed restriction. Results at the end of the experiment showed that total number of eggs laid as well as Hen Day Production (HDP%) were significantly highest in hens previously subjected to SAD feeding for 6 weeks during rearing (p &lt; 0.05). Although feed intakes of pullets were significantly reduced by subjecting pullets to periods ranging from 2 – 8 weeks of SAD feeding during rearing (p &lt;0.05), feed intakes during laying period were not significantly affected (p&gt;0.05). However, feed per dozen egg as well as cost per dozen egg were significantly reduced among hens previously subjected to either 6 or 8 weeks of SAD feeding during rearing (p &lt; 0.05). Egg weight as well as egg diameter were similar among hens in all dietary treatments (p &gt; 0.05). SAD feeding programme did not significantly affect hens livability (p &gt; 0.05). It was concluded that, subjecting black harco hens to SAD feeding for 6 weeks during rearing period in place of ad libitum feeding, could improve laying efficiency. &#x0D;

Southwestern Atlantic reef-building corals Mussismilia spp. are able to spawn while fully bleached

Bleaching events are becoming more frequent and intense worldwide. Southwestern Atlantic corals are considered stress-tolerant species that suffer less during bleaching episodes. Therefore, we investigated if the reef-building corals Mussismilia hispida and M. harttii are capable of spawning while fully bleached. We compared spermatozoa concentration and motility, egg diameter and embryo viability between seemingly healthy and bleached colonies for both species. Findings show that both species spawned viable gametes. Concentration and motility of newly-released spermatozoa were similar between healthy and bleached colonies for both species. Unlike M. hispida, a 10% reduction in size was found in egg diameter for M. harttii. Embryo viability for bleached M. hispida colonies did not decrease; for bleached M. harttii there was a reduction from 14.7 to 6.3%, but fertilization and larval development still took place. These findings describe the unprecedented episode of corals spawning viable gametes when entirely bleached, supporting the suggestion of greater resilience for Southwestern Atlantic corals.