Spermatophore Quality Research Articles

Application of 17α-methyltestosterone to enhance broodstock maturation of the domesticated black tiger shrimp (Penaeus monodon): A comparative study of injection method and oral method

The effects of 17α-methyltestosterone administration on spermatophore quality in captive broodstock of tiger shrimp Penaeus monodon were investigated using injection method and oral method based on the optimized protocol. The experiment was designed to compare the oral administration group and injection group with two replications during a 38-day experimental period. Captive male broodstock of tiger shrimp weighing 57-95 g was collected from ponds and stored in a 10,000 m3 concrete tank (20 shrimp/tank). Male broodstocks were injected and orally administrated with 17α-methyltestosterone at the dose of 300 ng/100 g body weight. Data indicates that the injection of 17α-methyltestosterone showed the percentage of mature broodstock count and the percentage of normal spermatozoa count 1.07 and 1.38% higher and significantly differs from oral administration through mixing in feed at the maturation stage. However, at the time of the maturation and 1st re-maturation of both the methods, the weight of the spermatophores and the number of spermatozoa did not show any difference. Based on the comparison of the two methods used, the results are obtained that the administration of the hormone 17α-methyltestosterone can be done both through mixing in feed and through injection, but the administration of hormones through injection gives better results than the broodstock matures first simultaneously.

Improved reproductive performance of captive male broodstock of tiger shrimp Penaeus monodon with 17α-methyltestosterone induction

The purpose of this study was to evaluate the influence of different 17α-methyltestosterone injection frequencies at optimal doses to improve the quality of spermatophore and reproductive performance of captive male broodstock of tiger shrimp Penaeus monodon. Broodstocks of tiger shrimp weighing 51-65 g for males and 86-161 g for females were collected from ponds and stored in a 3,000 m3 concrete tank. Male broodstocks were injected with 17α-methyltestosterone at the optimized protocol at 300 ng/100 g body weight at different injection frequencies, three times, four times, and five times at seven-day intervals. As a control, male broodstocks were injected with a saline solution to determine the spermatophore quality. Evaluation of the reproductive performance of the captive male was observed in the captive female broodstock tiger shrimp using artificial insemination. The weight of spermatophore (0.041 g), gonadosomatic index (7.71%), the total number of spermatozoa (64 × 106 cells/mL) significantly increased, and the percentage of abnormal spermatozoa significantly decreased by 73% as well as hatching rate increased to 43.14% at the injection frequency of four times compared to the other treatments. In conclusion, injection of 17α-methyltestosterone at the dosage of 300 ng/100 g body weight at the frequency of giving four times was effective enough to improve the reproductive performance of captive tiger shrimp. Therefore, the method proposed can be a strategy to produce better larvae and increase the income of the aquaculture business.

Dietary macronutrient balance and fungal infection as drivers of spermatophore quality in the mealworm beetle.

Males of many insects deliver ejaculates with nutritious substances to females in the form of a spermatophore. Different factors can affect spermatophore quality. We manipulated males' diet and health to determine the balance of macronutrients deposited in the spermatophores of Tenebrio molitor beetles. For diet, we varied the concentration of proteins and carbohydrates, while for health status we used a fungal infection. Males with different condition copulated with unmanipulated females, and spermatophores were extracted to measure the amount of proteins, lipids and carbohydrates. Diet and infection had an effect on the quality of the spermatophore. Diets with high protein and low carbohydrate contents produced spermatophores with higher protein, carbohydrate, and lipid contents. In contrast, diets with little protein and high in carbohydrates led to low quality spermatophores. Infected males produced spermatophores with the highest amount of all three macronutrients. In general, spermatophore content was carbohydrates>proteins>=lipids. The fact that sick males produced richer spermatophores can be explained as a terminal investment strategy. The large investment of carbohydrates may be related to the preparation of spermatozoa in males, and eggs in females.

Body coloration, carotenoid content, spermatophore quality and biochemical parameters by effect of temperature in the caridean shrimp Neocaridina davidi (Atyidae)

AbstractThis study analysed the effects of three temperatures (20, 24 and 28ºC) on survival, body coloration, carotenoid content, body weight, biochemical composition and spermatophore quality in the shrimp Neocaridina davidi. In all treatments, survival was >90%. Female body coloration and total carotenoid content, for both males and females, did not statistically differ among treatments. Female weight was similar for the three temperatures, while male weight was higher at 20ºC and 24ºC. Total lipid content was higher in female and male shrimps raised at 20ºC. Total protein content was higher in females exposed at 28ºC, but in contrast, males showed the lowest value at the same temperature. The histological and histochemical analyses of the male reproductive system did not reveal differences among treatments. At 20ºC, a delay in ovaries maturation was observed, as well as a smaller amount of ovigerous females at the end of the experimental period. Hence, these results suggest that a temperature range from 20ºC to 28ºC is adequate for satisfactory growth, with no change being exerted on spermatophore quality, body female coloration or carotenoid content, but biochemical composition was affected. Nevertheless, the lowest temperature had a clear impact on the metabolism and reproduction of N. davidi.

Effect of diets on carotenoid content, body coloration, biochemical composition and spermatophore quality in the “red cherry” shrimpNeocaridina davidi(Caridea, Atyidae)

In aquarium industry trade markets, Neocaridina davidi, the “red cherry” shrimp, is one of the most attractive ornamental shrimps due to the striking reddish coloration of females. Five commercial diets formulated for ornamental species were evaluated over a 90-day period in N. davidi males and females, based on survival, biochemical composition, body weight, carotenoid content and body coloration. Furthermore, histological and histochemical analyses of the male reproductive system were performed to evaluate the spermatophore quality. In all treatments, survival was >80%, and protein content was similar in both female and male shrimps. Lipid content was higher in females and males fed on a diet having the highest lipid level. Carotenoid content was higher and body coloration was brighter in females and males fed on a diet containing the highest carotenoid level. Histological and histochemical analyses of the spermatophore structure and composition showed no differences among diets, suggesting that the five commercial diets are adequate for satisfactory growth and spermatophore quality of N. davidi. The diverse sources and quantities of carotenoids in the highest carotenoid level diet render it more suitable for colour enhancement of this species.

DETERMINE THE COMPETENCE OF DIFFERENT FRESH DIETS TO IMPROVE THE SPERMATOPHORE SUPERIORITY OF GIANT BLACK TIGER SHRIMP, PENAEUS MONODON (FABRICIUS, 1798)

The intention of the present study was to assess the effect of fresh natural food on spermatophore quality and analysis by the way of sperm weight, count, viability as well as the proximate analysis of offered food and shrimp brood stock. The experiment was carried out with the three following treatments; fresh squid, polychaete and beef liver up to 5 weeks. All parameters were measured by the starting of 3 rd week (15 days) and the end of the (35 days) of the experiment. Spermatophore quality was evaluated by spermatophore weight, sperm count, viability and proximate analysis of the treatment and shrimps. The content of three essential fatty acids, Arachidonic acid (AA), Eicosapentanoic acid (EPA) and Docosahexaenoic acid (DHA) from wild Penaeus monodon brood stock were evaluated in comparison with natural diet fed to P. monodon . Spermatophore of wild male brood stock contained higher levels of AA than those of artificial fed males. Polychaete has higher proportion of AA to EPA and DHA. At the end of the treatment the sperm viability and count, shrimp and spermatophore weight were significantly different among treatment and control (p<0.05). The present study concludes that the fresh squid diet is highly preferred over the diets influence on increasing the spermatophore quality, therefore use of fresh squid only is recommended for the maturation of male P. monodon brood stock. // //

What makes a good mate? Factors influencing male and female reproductive success in a polyphagous moth

The mating propensity of an individual is expected to depend on the costs and benefits of mating, which may vary across the sexes and across different mating opportunities. Both males and females should gain fitness either by mating with multiple mates and/or by mating with higher quality mates. Therefore, an important question in the area of sexual selection concerns what makes an optimal mate. From a female perspective, females are expected to prefer males providing direct material benefits for the present generation and/or indirect genetic benefits for their offspring in the subsequent generation. Because the male's contribution to these benefits can be limited, as reproduction imposes nontrivial costs on males, the female's benefits from mating can vary markedly as a function of the condition of her mate. In capital breeding species, in which males invest most of their larval resources in a single reproductive event, the females are likely to prefer to mate with virgin males in good condition (i.e. males that have developed on high-quality food sources). In this study we used the European grapevine moth, Lobesia botrana, to test experimentally whether the larval nutrition and mating history of males influence their quality as mates. We provided wild L. botrana males originating from different cultivars and vineyards with unlimited access to standardized females, and examined the lifetime reproductive success of the males and the consequences for the reproductive output of females. Our results show that ‘male quality’ depended on both the male larval origin and mating history, and that females discriminated between males and mated more with males having high spermatophore quality (virgin males and males from certain cultivars or vineyards) to obtain substantial direct benefits.

Spermatophore Quality and Production in two Heliconius Butterflies with Contrasting Mating Systems

Male investment in spermatophore quality is a function of the degree of polyandry. Among butterflies and other organisms that provide gifts, polyandry tends to select for gifts of better quality than monandry. Tropical butterfly species Heliconius erato and H. melpomene differ in mating systems and provide an ideal system to test expectations regarding allocation to spermatophore quality and production. Heliconius erato males mate with females while they emerge from pupa. Females mate for life and show no mate choice. In H. melpomene, females are courted by males and may mate several times in their lifetime. In order to evaluate whether spermatophore quality (mass and protein content) differed between the two species we conducted mating experiments with virgin males and virgin females in an outdoor insectary. In order to study the dynamics of spermatophore production during subsequent matings, males were also allowed to mate two or more times. Spermatophores of virgin H. melpomene males contained significantly more protein than those of H. erato, confirming theoretical expectations; spermatophore mass was not different. The polyandrous species also showed a significant reduction in mass and protein content in the second mating, while H. erato responses were mixed but non significant. Additionally, the effect of time between successive matings was dependent on species identity. Our results confirm that polyandrous Heliconius invest more in spermatophore quality than its monandrous congener. Two explanations are suggested for the observed loss of mass and protein content in polyandrous Heliconius, potential cost for production or strategic ejaculation.

The effect of environmental cues and neurotransmitters on male sexuality of the eastern Pacific Penaeus ( Litopenaeus) species

This research evaluates the effect of ecosystem anomalies during El Niño 2009–2010 and the role of serotonin and the dopamine antagonist: spiperone over the male reproductive mechanism of three species of the sub-genus Litopenaeus from the Gulf of Nicoya, Costa Rica. Wild males of Penaeus (Litopenaeus) stylirostris and Penaeus (Litopenaeus) occidentalis were captured during 2009–2010 for spermatophore quality analysis, complemented with sexual performance under captivity. Additionally, these species and Penaeus (Litopenaeus) vannamei were used to study the role of serotonin alone and in combination with spiperone on male sexual maturation, using spermatophore quality parameters as indicators. Our findings indicate that during El Niño 2009–2010 the adult male population of P. stylirostris and P. occidentalis suffered a distinctive reproductive declined of reversible nature since after moving males to a stable environment (maturation laboratory conditions), in the same geographical location, both species improved significantly their sexuality in a short period of time, particularly P. stylirostris. These findings suggest that environmental cues are a primary controlled mechanism for spermatophore production and that captivity do not affect negatively the sexual status of wild Litopenaeus. Therefore, it seems that both species are capable of reaching their optimum sexual potential under controlled reproduction conditions by managing the environment adequately. Comparative studies in following years will help to clarify the relative contributions of El Niño event and fishery overexploitation over male shrimp sexuality. Concerning the role of neurotransmitters, serotonin at 25 μg g − 1 body weight (b.w.; 10 − 6 mol animal − 1 ) did not induce any improvement on spermatophore quality of P. stylirostris and P. vannamei. Moreover, serotonin plus spiperone (2 μg g − 1 b.w.; 10 − 7 mol animal − 1 ) injection in P. stylirostris, P. vannamei and P. occidentalis, induced some degree of negative sexual response. These findings suggest that serotonin and dopamine play a different reproductive role in males and females of Litopenaeus; the relative importance of the major known endocrine pathways is discussed.

Spermatophore quality of the pink shrimp Farfantepenaeus paulensis (Decapoda, Dendrobranchiata) broodstock fed with different maturation diets

The objective of the present work was to evaluate the effects of different diets on spermatophore quality and tissue biochemical composition in male pink shrimp Farfantepenaeus paulensis. The experiment was carried out with the three following treatments: fresh food, commercial diet and a mix of fresh food and commercial diet. Spermatophore quality was evaluated by spermatophore weight, sperm count, melanization and spermatophore absence rates. Biochemical analyses of glucose, triacylglycerides and protein were completed for hemolymph, hepatopancreas and muscle. Spermatophore weight and sperm count were not significantly different among treatments (P > 0.05). At the end of the experiment, shrimp fed only with commercial diet showed highest melanization rate and spermatophore absence, 42.85% and 42.85%, respectively. To shrimp fed only with fresh food the values melanization and spermatophore absence were 15.38% and 0%, respectively and the mix 12.51% and 37.50%, respectively. Hemolymph glucose concentration was significantly higher in commercial diet treatment (31.19 mg/dL) than fresh food (12.24 mg/dL) and mix treatments (10.97 mg/dL). Farfantepenaeus paulensis broodstocks fed only the commercial diet may present decrease spermatophore quality.

Preliminary evaluation of the effect of juvenile hormone III and methyl farnesoate on spermatophore quality of the white shrimp, Litopenaeus vannamei Boone, 1931 (Decapoda: Penaeidae)

Este estudio preliminar es un primer paso en la exploracion del efecto de la hormona juvenil III (HJ III) y el metil farnesoato (MF) sobre la calidad de espermatoforos de Litopenaeus vannamei. La HJ III aplicada cinco veces a una dosis de 109 ng g-1 de peso corporal (p.c.) durante 58 dias, no mejoro el conteo de espermatozoides en comparacion con el grupo control (P>0,05). La anormalidad de espermatozoides disminuyo en las regeneraciones sucesivas de espermatoforos de manera similar en machos tratados con HJ y machos control (P>0,05). Por el contrario, un total de cinco aplicaciones semanales de MF a 120 ng g-1 p.c. causo un incremento significativo en numero de espermatozoides y una disminucion en anormalidad de espermatozoides (P 0,05)

Experimental broodstock diets as partial fresh food substitutes in white shrimp Litopenaeus vannamei B.

In the first experiment, conducted in a research facility, Litopenaeus vannamei broodstock were fed either a 100% fresh food control treatment (FRE, consisting of frozen squid, oyster, mussel and enriched Artemia biomass in a 2.3:1.4:1.3:1 dry matter ratio) or one of the two treatments in which 50% [dry matter (DM)] of the fresh food was substituted with experimental artificial diets: a dry diet based on freeze-dried Artemia biomass (ART) and a control dry diet (CON). In the second experiment, conducted in a commercial hatchery, shrimp broodstock were fed either a fresh ration (FRE, consisting of frozen squid, polychaetes and enriched Artemia biomass in a 2.5:1.5:1 DM ratio) or the same experimental artificial diets (ART and CON) replacing 50% of the DM by elimination of polychaetes and Artemia biomass. In experiment 1 treatments CON and ART produced better results (P=0.05) than treatment FRE in terms of spawn performance and egg production per female. In experiment 2 no differences were detected among treatments FRE and CON whereas treatment ART performed better (P=0.05) in terms of spawning, egg production per female and spermatophore quality. Broodstock survival and offspring quality did not differ between treatments in either experiment.

Effect of 17α‐Methyltestosterone and 17α‐Hydroxyprogesterone on the Quality of White Shrimp Penaeus vannamei Spermatophores

Abstract.— Controlled reproduction of penaeid shrimp requires a better utilization of males by sperm quality monitoring and sperm quality improvement. Spermatophores of white shrimp Penaeus vannamei were improved, in terms of increased sperm count, spermatophore weight, and a reduced incidence of sperm abnormalities by a single injection of 17α‐methyltestosterone at 0.01 or 0.1 μg/g body weight. 17α‐hydroxyprogesterone did not induce a significant improvement in spermatophore quality. These findings indicate that a steroid injection program should be evaluated as a practical way of improving spermatophore quality in commercial operations.

Egg Water Induced Reaction and Biostain Assay of Sperm from Marine Shrimp Penaeus vannamei: Dietary Effects on Sperm Quality

AbstractReproductive performance was evaluated for sexually mature male Penueus vannamei fed one of four diets: 1) commercial 40% protein shrimp growout diet; 2) 100% squid; 3) 50% squid, 25% bloodworms and 25%Artemia; and 4) starvation. Spermatophores were ejaculated manually from tagged males at stocking and every 12 d thereafter. For each half of the compound spermatophore, weight and sperm count were determined. Four methods were used to assay the sperm quality: 1) gross morphology (GM); 2) trypan blue stain (TB); 3) acridine orange stain (AO); and 4) egg water induced reaction (EW). The reaction induced when P. vannamei sperm are exposed to conspecific egg water is grossly similar to that observed in vivo at the surface of the freshly spawned eggs from naturally mated females. Little correlation was found between spermatophore weight and sperm count. The best correlation was found between GM and AO (r2= 0.859, P &lt; 0.01). Many morphologically abnormal sperm did not stain with TB. For most of the spermatophores evaluated; over 80% of the sperm were morphologically normal, were unstained with TB, and were immediately fluorescing light green when stained with AO. When exposed to egg water, sperm from these apparently good quality spermatophores yielded mixed results. The analysis of dietary effects on spermatophore quality were equivocal. Although a significant decline in body weight, spermatophore weight, and sperm count were observed in the starvation treatment as compared to maturation and squid diets, no significant differences were observed in MY of the sperm quality assays.

Development and Deterioration of Spermatophores in Pond‐Reared Penaeus vannamei

AbstractSpermatophore deterioration in pond‐reared Penaeus vannamei was studied, and spermatophore quality was evaluated and improved. Sperm production of males collected from grow‐out ponds was increased by two techniques: eyestalk ablation using a fresh frozen maturation diet (13% body weight); and laboratory culture using a diet of the formulated feed Nicovita Plus (3% body weight/ d) and frozen squid (2%). Findings are complementary to previous reports that eyestalk ablation improves quality of spermatophores in young (25.7 g) males. The timing of eyestalk ablation for activation of the endocrine mechanism, leading to improved spermatophore quality was also explored. After eyestalk ablation, performed between postmolt and intermolt stages, 26 g males required a minimum of three spermatophore regenerations or 42 d to significantly increase spermatophore size and sperm count. On the other hand, the laboratory culture (2.5 mo) technique improved the quality of spermatophores in successive regenerations for non‐ablated males. In the present study, subadult P. vannamei produced spermatophores which, if not transferred or manually ejaculated, gradually deteriorated (successive stages are described), while a new compound spermatophore was being synthesized.

Reproductive Quality Evaluation of Male Penueus stylirostris from a Grow‐Out Pond

AbstractSeveral male Penucus stylirostris were selected from a 3 ha commercial earthen pond and were individually evaluated for reproductive performance. Indicators measured were compound spermatophore weight, sperm count, and sperm abnormalities.It was found that spermatophore quality was significantly better for 30–40 g shrimp than for 20–30 g shrimp (P &lt; 0.05). The higher frequency of abnormalities measured in younger males and the inverse relationship between abnormalities and sperm count indicate that the vas deferens could be the tissue responsible for producing highly abnormal immature semen. It is proposed that male maturation has at least three independently controlled levels of organization: testes maturation, vas deferens maturation, and spermatophore synthesis.The individual evaluation showed that each male followed a particular response in reproductive quality. Changes in spermatophore weight were not an indicator of sperm density within spermatophores.Male reproductive tract degenerative syndrome (MRTDS) and male reproductive system melanization (MRSM) did not develop in any shrimp during these experiments.