Sperm Quality Over Consecutive Spermatophore Regenerations in the Pacific White Shrimp Litopenaeus vannamei
01 Jun 2004-Journal of The World Aquaculture Society (Journal of the World Aquaculture Society)-Vol. 35, Iss: 2, pp 178-188
TL;DR: This procedure allows selecting individuals with high baseline sperm quality based on significant correlations between baseline and regenerated sperm quality observed in the present work, and indicates that the existing spermatophores at stocking of males should be expelled to have higher sperm quality in regenerated sperMatophores.
Abstract: The reproductive potential of males plays an important role in the productivity of captive penaeids. Males present a large variability in their reproductive potential, and thus the selection of appropriate males for reproduction is highly desirable. The present study compares sperm quality at the beginning of the experiment (baseline values) with variations in sperm quality as a result of consecutive spermatophore regenerations. This was done to evaluate possible predictive criteria for optimal sperm quality based on morphological and biochemical criteria in pond-reared Pacific white shrimp Litopenaeus vannamei males. Sperm quality was similar between left and right spermatophore. Sperm count and proportion of normal sperm increased by 86 and 65% (P < 0.05) respectively, from baseline values to third spermatophore regeneration. Proportion of dead sperm progressively decreased with consecutive regenerations, attaining values 33% lower by the third regeneration, compared to baseline values. This indicates that no decrease in sperm quality occurs in L. vannamei during consecutive regenerations and that the existing spermatophores at stocking of males should be expelled to have higher sperm quality in regenerated spermatophores. Furthermore, this procedure allows selecting individuals with high baseline sperm quality based on significant correlations between baseline and regenerated sperm quality observed in the present work. Baseline values of glucose concentration in the hemolymph were positively correlated to baseline values of sperm count (r = 03, P < 0.05). In contrast, baseline values of several lipids in the hemolymph were negatively correlated to several traits of sperm quality at first sampling (baseline values) or at first regeneration. These results are discussed in terms of nutritional requirements of males and of possible predictive criteria of sperm quality.
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TL;DR: This review evaluates the current knowledge on male reproduction of open thelyca penaeoid shrimps, a group of shrimp that belongs to the genus Penaeus, sub-genus Litopenaeus, and presents a unique reproductive model, characterized by complex spermatophores and thelycas without seminal receptacles.
Abstract: Male reproductive performance in penaeoid aquaculture is a major issue. This review evaluates the current knowledge on male reproduction of open thelyca penaeoid shrimps. This group of shrimp belongs to the genus Penaeus, sub-genus Litopenaeus, and presents a unique reproductive model, characterized by complex spermatophores and thelyca without seminal receptacles; however, sperm seem to reach maturation and capacitation on the open thelyca. Males of this group adapt differently to captivity, being P. (Litopenaeus) vannamei the best adapted species. Nevertheless, three problematic conditions develop in confined environments in one or more species: male reproductive tract degenerative syndrome (MRTDS), male reproductive system melanization (MRSM), and spermatophore deterioration (SD).
58 citations
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TL;DR: This is the ¢rst study to report high fertilization and hatch rates from cryopreserved spermatophore using arti¢cial implantation of sperMatophore before spawning.
Abstract: To develop an appropriate cryopreservation protocol for spermatophores of black tiger shrimp, Penaeus monodon, three cryoprotectants (dimethyl sulphoxide (DMSO), methanol (MeOH) and ethylene glycol (EG)) at two concentrations (5% and 10%) were examined. Arti¢cial implantation of spermatophores was also carried out to assess the fertilizing ability of fresh and post-thaw spermatophores. Spermatophores were collected during consecutive regenerations (15-day intervals) and assessed for qualitative and quantitative changes and also for fertilizing ability by implantation. The mean fertilization rate for arti¢cial insemination using post-thaw spermatophore was 79.9 3.7%, lower than the fertilization rates observed for arti¢cial implantation using fresh spermatophore and natural mating. Mean hatch rates for fresh spermatophore, frozen-thawed spermatophore and natural mating were 88.8 0.6%, 87.8 0.4% and 88.3 0.5%, respectively; and there was no difference among the three groups. The mean fertilization rate of spermatophores collected during the ¢rst stripping was higher (90.6 0.6) than during the second stripping (85.7 2.6), but the mean hatch rate was not diierent between the two strippings. The highest mean sperm viability (79.7 0.4%) was obtained from DMSO (5%), with no survival observed in the 10% MeOH treatment. Spermatophore weight, total sperm count and percentage of abnormal sperm were not diierent between spermatophores collected at the ¢rst and second stripping. This is the ¢rst study to report high fertilization and hatch rates from cryopreserved spermatophore using arti¢cial implantation of spermatophore before spawning.
39 citations
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TL;DR: This is the first report of males of any animal species exhibiting endogenous reproductive cycles, as do females, and of the finding that spermatozoa have a predetermined expiry date, a feature that may possibly contribute to male fitness.
Abstract: That sexually mature females go through hormonally regulated reproductive cycles is a well-established phenomenon in sexually reproducing organisms. Males, on the other hand, are commonly regarded as being continuously ready to mate. 'Programmed sperm degradation' on a periodic basis or an innate sperm 'expiry date' have never been shown. This manuscript describes a newly discovered molt-dependent mechanism by which old sperm is periodically removed from the reproductive system of male Litopenaeus vannamei shrimp. Firstly, it is shown that the spermatophores of males held in captivity become progressively melanized, a process that eventually renders them impotent. Then, by using melanin specks as a color marker, it is demonstrated that this phenomenon can be delayed and even reversed as long as the males remain sexually active. Lastly and most importantly, it is shown that male shrimp go through reproductive cycles that are strictly associated with their molt cycles, which, in turn, are hormonally regulated. Intact intermolt spermatophores disappeared about 12 h premolt, and a new pair of spermatophores appeared in the ampoules the day after the males had molted. This phenomenon was observed in an almost constant portion of males, both those in an all-male population and those in mixed male/female populations, even during the times that the females of those populations were not vitellogenically active. To the best of our knowledge, this is the first report of males of any animal species exhibiting endogenous reproductive cycles, as do females, and of the finding that spermatozoa have a predetermined expiry date, a feature that may possibly contribute to male fitness.
38 citations
Cites background from "Sperm Quality Over Consecutive Sper..."
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TL;DR: Broodstock management appears to have maintained genetic diversity, because mean allele numbers were similar to the pooled values from a single hatchery sampled between 2000 and 2002, however, with an observed heterozygosity below Hardy–Weinberg expectations and a high mean inbreeding coefficient it would be timely to introduce cross breeding among hatcheries to reduce the risk of inbreeding depression.
Abstract: The Mexican shrimp culture industry is based upon Penaeus (Litopenaeus) vannamei broodstock with a presumed common genetic origin and more than 10 generations of closed breeding. This has raised concerns about the low level of genetic diversity and accumulated inbreeding in these broodstock. Inbreeding depression can lead to low performance of hatchery-reared shrimp, and an evaluation of the genetic diversity can significantly enhance broodstock management. In this study, we evaluated the genetic composition and diversity of broodstock from six hatcheries from Northwestern Mexico, and estimated their inbreeding levels based on DNA microsatellite markers. A total of 658 individuals were analyzed with six microsatellite loci. Medium mean genetic diversity values (8.98 alleles per locus) and heterozygosity (0.57) were higher than anticipated. There was significant variation in the genetic composition of broodstock from different hatcheries. All the hatchery broodstock were significantly different from a wild population from the state of Sinaloa. The most common alleles were the same in broodstock from all six hatcheries. None of the hatchery stocks has uniquely distinctive alleles. Broodstock management appears to have maintained genetic diversity, because mean allele numbers were similar to the pooled values from a single hatchery sampled between 2000 and 2002. However, with an observed heterozygosity ( H o ) below Hardy–Weinberg expectations and a high mean inbreeding coefficient (26.5%) it would be timely to introduce cross breeding among hatcheries to reduce the risk of inbreeding depression.
36 citations
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TL;DR: Developing a protocol for the chilled storage of white shrimp spermatophores and evaluating bacterial propagation during such storage to generate a consistent and reliable supply of spermatozoa for domestication purposes is developed.
Abstract: Chilled storage of spermatophores from white shrimp (Litopenaeus vannamei) is needed to generate a consistent and reliable supply of spermatozoa for domestication purposes. The objective of this study was to develop a protocol for the chilled storage of white shrimp spermatophores and to evaluate bacterial propagation during such storage. In the first experiment, spermatophores were immersed in four extenders, mineral oil, Ringer's solution, phosphate buffer and 0.85% NaCl, and stored at low temperature (2–4 °C) for 35 days. Characteristics of preserved spermatophores changed the least and viable sperm was highest when spermatophores were stored in mineral oil. Spermatophores preserved with mineral oil appeared morphologically normal. Bacillus circulans, Staphylococcus hominis and S. lugdunensis, S. sciuri, S. xylosus and Micrococcus spp. were identified as the predominant bacteria during chilled storage, and total bacterial counts gradually increased during the experiment. A second experiment investigated the effect of antibiotic on chilled storage. Spermatophores were preserved in only mineral oil or mineral oil with 0.1% penicillin–streptomycin. These were evaluated for changes in external morphology of spermatophores, sperm viability and total bacteria count every week during a 35-day experimental period. Percentages of viable sperm (69.5 ± 3.9%) were significantly higher (P
33 citations
References
More filters
[...]
TL;DR: This assay is very reproducible and rapid with the dye binding process virtually complete in approximately 2 min with good color stability for 1 hr with little or no interference from cations such as sodium or potassium nor from carbohydrates such as sucrose.
Abstract: A protein determination method which involves the binding of Coomassie Brilliant Blue G-250 to protein is described. The binding of the dye to protein causes a shift in the absorption maximum of the dye from 465 to 595 nm, and it is the increase in absorption at 595 nm which is monitored. This assay is very reproducible and rapid with the dye binding process virtually complete in approximately 2 min with good color stability for 1 hr. There is little or no interference from cations such as sodium or potassium nor from carbohydrates such as sucrose. A small amount of color is developed in the presence of strongly alkaline buffering agents, but the assay may be run accurately by the use of proper buffer controls. The only components found to give excessive interfering color in the assay are relatively large amounts of detergents such as sodium dodecyl sulfate, Triton X-100, and commercial glassware detergents. Interference by small amounts of detergent may be eliminated by the use of proper controls.
214,383 citations
[...]
TL;DR: The phosphosulphovanillin method, previously used only for blood serum samples, is recommended for estimation of ‘total’ lipids in the tissue of marine animals, based on using a cholesterol standard which has previously been related to gravimetric values obtained on blood sera.
Abstract: A reliable and simple method for the estimation of ‘total’ lipids in the tissue of marine animals is much needed for biochemical-ecological work. As a result of the present investigations the phosphosulphovanillin method used, hitherto, only for blood serum samples, is recommended. The method depends on using a cholesterol standard which has previously been related to gravimetric values obtained on blood sera. The colorimetric values have been compared with gravimetric results on a variety of marine tissues — largely of invertebrates. The data given in the tables may be used to convert colorimetric values, using a cholesterol standard to total lipids. For extended investigations, however, it is recommended that the cholesterol values are first calibrated against gravimetric values for the particular tissue under investigation. A summary of the preparation of reagents and procedure is given.
702 citations
[...]
TL;DR: Evidence for the existence or formation of at least two water-insoluble glycogen complexes in liver was presented and losses of glycogen in the ethanol precipitation step were found to be preventable by the use of a coprecipitant.
Abstract: Some physical properties of glycogen have been investigated and applied to micro isolation and assay in biological material containing only a few micrograms of glycogen. Losses of glycogen in the ethanol precipitation step were found to be preventable by the use of a coprecipitant, of which Na2SO4 was the most satisfactory. Evidence for the existence or formation of at least two water-insoluble glycogen complexes in liver was presented. Treatment at 100°C with concentrated KOH for 20 hr rendered all glycogen soluble in water.
509 citations
[...]
TL;DR: This paper reviews the current knowledge on shrimp broodstock nutrition with special reference to developments during the last decade and an overview of the efforts to reveal the nature of maturation-stimulating factors in fresh food, and of the use and performance of commercial and experimental artificial diets.
Abstract: This paper reviews the current knowledge on shrimp broodstock nutrition with special reference to developments during the last decade. Biochemical studies and diet studies are discussed with the aim of identifying the nutrients that are important to sustain optimal shrimp maturation, reproduction and offspring quality. Additionally, an overview is given of the efforts to reveal the nature of maturation-stimulating factors in fresh food, and of the use and performance of commercial and experimental artificial diets.
210 citations
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TL;DR: This review focuses on the different criteria currently used to assess offspring quality of penaeid shrimp and the factors that affect this characteristic.
Abstract: This review focuses on the different criteria currently used to assess offspring quality of penaeid shrimp and the factors that affect this characteristic. The term ‘larval quality’ generally refers to the physiological condition of the larvae and is related to survival and growth rates during several larval developmental stages. The criteria fit into five general categories, depending on the approach used: biochemical, morphological, behavioral, production and survival to stress tests. Several variables at the broodstock management level are known or suspected to affect larval quality. These include variables that can be more easily controlled by producers or researchers than others. Broodstock nutrition is probably the best reviewed aspect and is supported by many papers on the metabolism of several components during maturation, use of fresh vs. artificial food and specific requirements of particular components, such as lipids and vitamins. Endocrine control of reproduction has been widely studied in crustaceans. Eyestalk ablation still represents the most commonly used endocrine manipulation to induce maturation and spawning. Other alternatives are considered although few evaluate larval quality and none has been used in production. More recently, the use of captive broodstock and genetic improvement programs have gained importance. The effect of other biological characteristics of shrimp, such as age and size, season of the year when induced to intensive maturation conditions, time spent in maturation tanks and consecutive spawnings are also considered.
170 citations