Structure and Function of the Vas Deferens in the Shrimp Penaeus Setiferus: Segments 1–3

Ro, Sarah; Talbot, Prudence; Leung‐Trujillo, Joanna R.; Lawrence, A. L.

doi:10.2307/1548335

Cited by 50 publications

(44 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In Melicertus (formerly Penaeus) kerathurus, a complete spermatophore is accommodated in the terminal ampoule while another is simultaneously forming in the medial vas deferens (Malek and Bawab, 1974a;Malek and Bawab, 1974b). Judging from the small variability in the dimensions of the medial vas deferens, Ro et al (Ro et al, 1990) concluded that the migration of a new spermatophore along the sperm duct does not occur at random but is under precise regulation. In other animals, almost all the current knowledge on sperm viability, longevity and storage duration, relates to the time after ejaculation while the sperm cells are inside the female reproductive tract (Birkhead and Moller, 1993;Parker, 1970;Saunders, 2002).…”

Section: Discussionmentioning

confidence: 99%

Males also have their time of the month! Cyclic disposal of old spermatophores, timed by the molt cycle, in a marine shrimp

Parnes

Raviv

Shechter

et al. 2006

Journal of Experimental Biology

View full text Add to dashboard Cite

SUMMARY 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.

show abstract

Section: Discussionmentioning

confidence: 99%

Males also have their time of the month! Cyclic disposal of old spermatophores, timed by the molt cycle, in a marine shrimp

Parnes

Raviv

Shechter

et al. 2006

Journal of Experimental Biology

View full text Add to dashboard Cite

show abstract

“…The integrity of the testicular mass is maintained by a thin epithelium while the internal mass itself is composed mainly of follicles and an anterior and posterior conducting tubule. Most decapods have multiple testicular lobes (Ro et al 1990), some of which may consist entirely of a single highly-coiled seminiferous tubule (King, 1948;Chow et al, 1991).…”

Section: Discussionmentioning

confidence: 99%

The spermatid pathway and associated reproductive structures of the squat lobsterThenus orientalis(Lund, 1793)

Burton

1995

Invertebrate Reproduction & Development

View full text Add to dashboard Cite

Invertebrate Reproduction and Development, 28:l (1995) 53-61 Balaban, Philadelphia/Rehovot 0168-8170/95/$05.00 O 1995 Balaban The spermatid pathway and associated reproductive structures of the squat lobster Thenus orientalis (Lund, 1793) SummaryThis study describes and identifies the relationship between sperm development and associated structures of the male reproductive system of the Scyllarid lobster Thenus orientalis. The male gonad of Thenus orientalis consists of paired testes, each with a vas deferens which terminates in a gonophore on the coxopodite of the fifth pereiopod.Internally the testis consists of numerous acini which are attached to coiled anterior and posterior collecting tubules. Within the acini, spermatogenesis occurs giving rise to spermatids which are liberated into the collecting tubules and subsequently grouped into spermatophores. Spermiogenesis continues as the spermatophores progress through the proximal, medial and distal vas deferens where maturity is reached. Movement through the vas deferens is assisted by apocrinal secretions of the glandular epithelium which probably functions both as a nutrient and lubricant. An external layer of smooth muscle which thickens progressively towards the distal vas deferens also assists in propelling the luminar matrix containing the spermatophores toward the gonophore.

show abstract

“…Among other factors, lack of spermatophore adhesiveness is believed to contribute to the lack of mating reported from many breeding trials (Alfaro and Lozano, 1993;Ceballos-Vazquez et al, 2004;Chamberlain et al, 1983;Leung-Trujillo and Lawrence, 1987;Pascual et al, 1998;Rosas et al, 1993). Adhesiveness is conferred by extracellular materials that are laid down on the spermatophore forming in each of the two ampoules (Bauer and Cash, 1991;Chow et al, 1991;King, 1948;Malek and Bawab, 1974;Ro et al, 1990). After ejaculation the two spermatophores have to be attached to one another and then to adhere to the female abdomen.…”

Section: Discussionmentioning

confidence: 99%

Dynamics of reproduction in a captive shrimp broodstock: unequal contribution of the female shrimp and a hidden shortage in competent males

Parnes¹,

Raviv²,

Azulay³

et al. 2007

Invertebrate Reproduction & Development

View full text Add to dashboard Cite

The major bottleneck in the breeding in captivity of penaeid shrimp is the fact that females do not spontaneously undergo vitellogenesis, which thus has to be induced endocrinologically by eyestalk ablation. Partial compensation for the low responsiveness of the females to this treatment is obtained by the use of very large broodstock populations. This old problem was newly approached in the current study by monitoring individual female life-spans and vitellogenic cycles in a small population of the Pacific white shrimp, Litopenaeus vannamei. Vitellogenic activity and spawning peaked during the second month of the four-month trial and decreased thereafter due to the sharp fall in the number of reproductively active females. Only about 75% of all the females in the broodstock were reproductively active, and most of them spawned for the first time, or exhibited fully vitellogenic ovaries, during the first two weeks post-ablation. Nevertheless, the best performing females, which comprised less than 20% of the female broodstock, matured more rapidly, exhibiting fully vitellogenic ovaries 4.1±3.4 days after eye-stalk ablation. These animals contributed more than 50% of the total eggs and nauplii produced. The total number of vitellogenic cycles recorded from all reproductively active females was 305, but in less than a third of these cycles were the females observed to be carrying spermatophores or sperm masses. Since females-but not males-in captivity undergo accelerated reproductive cycles due to the endocrine induction, it is suggested that the lack of mating consistently reported from maturation systems may be due to the lack of sufficient ready-to-mate males.

show abstract

Structure and Function of the Vas Deferens in the Shrimp Penaeus Setiferus: Segments 1–3

Cited by 50 publications

References 4 publications

Males also have their time of the month! Cyclic disposal of old spermatophores, timed by the molt cycle, in a marine shrimp

Males also have their time of the month! Cyclic disposal of old spermatophores, timed by the molt cycle, in a marine shrimp

The spermatid pathway and associated reproductive structures of the squat lobsterThenus orientalis(Lund, 1793)

Dynamics of reproduction in a captive shrimp broodstock: unequal contribution of the female shrimp and a hidden shortage in competent males

Contact Info

Product

Resources

About