Spermatophore Production Research Articles

Spermatogenesis and spermatophore production in the hawaiian red lobster Enoplometopus occidentalis (Randall) (Crustacea, nephropidae).

Light microscopy of the male reproductive tract of the Hawaiian red lobster Enoplometopus occidentalis documented the cyclic nature of spermatogenesis and spermatophore formation. Testes are composed of a convoluted collecting tubule bearing many spermatogenic follicles, all within a supporting mesentery. Spermatogonia are restricted to the basal side of the follicular epithelium and proliferate at onset of spermateleosis within the same follicle. Two generations of spermatogenic cells thus occupy each follicle, and accessory cells in the follicle form a basophilic epithelium between them. These accessory cells may detach with the spermatozoa at spermiation. The vas deferens lies outside the testicular mesentery and consists of a coiled proximal portion in which spermatophore production commences. Clusters of spermatozoa are here surrounded by a PAS-positive primary spermatophore layer, and a PAS-negative outer bounding layer is initiated. Completed further distally in the vas deferens, the outer bounding layer is thinner on the side of the spermatophore which adheres to the substratum after ejaculation; the thick side of this layer forms a broad cap. Outer circular and inner longitudinal muscular layers become well developed in the distal loop and descending portions of the vas deferens. The terminal portion of this duct contains no spermatophore prior to ejaculation. It has a longitudinally folded epithelium and an attached tubular gland which produces an extra-spermatophoral, gelatinous secretion. The androgenic gland is associated with this terminal segment of the vas deferens. These features are compared with those reported for other lobsters.

Reproductive activity of Mixodiaptomus laciniatus (Copepoda, Calanoida) in a high mountain lake (La Caldera, Granada, Spain)

A study on the reproduction of M. laciniatus in Lake La Caldera during the ice-free period of the years 1975, 1976 and 1977 has been carried out. Values obtained as to sex ratio, production of spermatophores and eggs as well as fecundity and reproductive rates have allowed us to establish two well-differentiated periods in the breeding season of the population: Mechanisms which determine both periods and their possible adaptive value, are discussed.

The effects of population density and sex ratio on mating frequency ofEarias insulana males and females in laboratory cultures

In laboratory populations ofEarias insulana Boisduval (Lepidoptera: Noctuidae) crowding did not affect spermatophore production by males or its acceptance by females. Sex ratio affected spermatophore transfer. A low male: female ratio resulted in the transfer of a large number of spermatophores per male. On the other hand, a high male: female ratio resulted in a high mating frequency of females. Egg production and hatching were not affected.

Patterns of sexual reproduction among parasitic platyhelminths.

Previous studies on the spermatogenesis and oogenesis of digeneans, monogeneans and cestodes are reviewed, including those in which isotopic labelling techniques have been utilized in order to determine the temporal duration of spermatogenic development stages. Similar labelling experiments have also provided information on the development and movement of oocytes in the female reproductive tract as well as indicating patterns of cell division and development in vitelline glands. The literature relating to the inseminative behaviour of parasitic platyhelminths is considered from a number of viewpoints including the patterns of cross- and self-insemination that occur in hermaphroditic digeneans, the mating behaviour of dioecious schistosomes, spermatophore production and insemination among monogeneans and the inseminative behaviour of polyzoic cestodes. The implications of selfing among parasitic platyhelminths are considered with respect to possible genetically deleterious consequences. In addition, consideration is given to the mechanisms underlying the fact that some species require cross-insemination or at least the presence of another worm in order to undergo normal growth and sexual development. Finally, experimental studies are reviewed which shed light on the strength of the barriers against hybridization that exist between well-defined species of parasitic platyhelminths.

EXAMINATION OF SPERMATOPHORE PRODUCTION BY LABORATORY‐MAINTAINED LOBSTERS (Homarus)

ABSTRACTLobster aquaculture requires control of reproductive processes. We have previously described an electrical stimulation technique for collecting spermatophores from living lobsters (Homarus americanus). These spermatophores can potentially be used in a variety of ways including: 1) experimental manipulation of sperm, 2) artificial insemination of females, 3) sperm banking, and 4) evaluation of sperm production by the male. In this study, we evaluated spermatophore production and extrusion from: 1) laboratory reared H. americanus and H. gammarus, 2) stressed, wild‐caught H. americanus, and 3) laboratory bred and reared hybrid males from reciprocal interspecific crosses. Our results show that the extrusion technique can be used successfully on H. americanus, H. gammarus and hybrid males. Laboratory reared H. americanus and H. gammarus from both Aquaculture Enterprises and Bodega Marine Laboratory extruded spermatophores in 60–85% of all trials. The majority of these spermatophores were of high quality containing large sperm masses with morphologically normal sperm. Stressed H. americanus, obtained from a market in Sunset Beach, California, 24 hours after shipment from New England, extruded fewer spermatophores which were shorter in length and inferior in quality. Hybrid males extruded spermatophores possessing a morphologically normal wall, but lacking sperm. These results demonstrate that this electrical stimulation technique can be used to screen males for spermatophore production and identify certain types of infertility.

Cellular Organization of the Testis and Spermatogenesis in Fishes

Synopsis. Tubular structure of the teleost testis can be divided into two basic types distinguished from each other by the distribution of spermatogonia. In most teleosts, spermatogonia occur along the length of the tubules, but in atheriniform fishes they are confined to the terrriinus of the tubule. Variations in these testis-types are discussed particularly in light of modifications leading to the production of spermatozeugmata or spermatophores. Teleost boundary are located immediately outside of the tubule basement mem? brane. Previous reports homologizing lobule boundary cells with Leydig or Sertoli are in error. Leydig have been described for species of teleosts wherein they have previously been thought to be absent and are a typical component of the interstitium. Sperm morphology reflects mode of reproduction. Nuclear elongation, coupled with possible elongation of the sperm midpiece, is characteristic of most species wherein fer? tilization is internal. Teleost sperm lack an acrosome.

WINTER CULTURE OF Penaeus vannamei IN PONDS RECEIVING THERMAL EFFLUENT AT DIFFERENT RATES

ABSTRACTPenaeus vannamei were cultured from 3 November 1978 to 10 April 1979 in eight 0.1‐ha ponds at the Texas A&M mariculture facility located at Central Power and Light Company's Barney M. Davis Power Station in Corpus Christi, Texas. Four treatments were established using 3 flow rates of thermal effluent (high, medium, and low) and 2 feeding rates (3 and 4%). Survival, growth, and distribution of shrimp within ponds were monitored using cast‐net sampling. The low‐flow ponds suffered 94% mortality during the first major cold front when temperatures dropped to 5.2°C. Survival increased strongly with each increase in flow rate to a maximum of 33.7–82.3% in high‐flow ponds. Low‐temperature mortality of P. vannamei appeared to begin below 8°C regardless of acclimation and to occur at temperatures as high as 12°C depending on acclimation. Growth rates among treatments ranged from ‐0.03 to 0.06 g/day with the highest rate found in the high‐flow ponds with 4% feeding rate. A regression of growth rates on mean temperatures for all ponds fed at the 3% rate indicated growth rates of 0.00 g/day at 15.9°C, 0.02 g/day at 20°C, and 0.05 g/day at 25.0°C. The 4% feeding rate treatment yielded greater survival, growth, food conversion efficiency, digestive gland index, and spermatophore production than the 3% feeding rate treatment. Cast‐net catches of shrimp artificially declined below 21°C, apparently due to increased burrowing activity. The distribution of P. vannamei within ponds indicated a preference for deeper waters during the day and a more even distribution at night.

Ecological and evolutionary significance of pelagic spermatophores of vermetid gastropods

Sperm are disseminated in vermetid gastropods by spermatophores released freely into the ocean. Spermatophores from 7 species of vermetids, including 3 genera, were obtained from reproductively active males or offshore plankton tows or both. Each vermetid spermatophore consists of a sperm mass containing highly ordered eupyrene and apyrene sperm enveloped concentrically by 3 transparent capsules. Generic and specific differences occur in the size, shape and composition of the sperm mass and capsule. The complexly layered spermatophore is assembled in the male reproductive tract, which includes and elaborate set of pallial reproductive glands for capsule production. Spermatophores are liberated by males into the seawater, and there dispersed by water movements. Some of these drifting spermatophores become entangled in the mucous feeding nets of female vermetids and are then activated by feeding movements. Activation of the complex ejaculatory apparatus appears to result from an interplay of osmotic and mechanical mechanisms. Spermatophores remain viable in the laboratory for 12 to 20 h after release from the male; after 20 h, the sperm mass breaks down and the sperm become immotile. Plankton tows capture some spermatophores with motile sperm and others in which sperm are no longer active. Evolutionary implications of the relationship between production of pelagic spermatophores, sessile mode of life and other aspects of vermetid biology are discussed.

Corpus allatum function during sexual maturation of male Diploptera punctata

ABSTRACT. The effect of allatectomy on synthesis of accessory reproductive gland secretion, spermatophore production and sexual behaviour in male Diploptera punctata was investigated during the first 6 weeks of adult life. After allatectomy, synthesis of the secretion and production of spermatophores was slightly reduced relative to sham‐operated animals (by 16%), but not relative to normal animals. However, sexual behaviour of the operated animals appeared normal. Thus, the corpora allata (CA) may not be necessary for the sexual functioning of male D.punctata. The synthesis of C16 juvenile hormone (C16 JH; JH III) by isolated pairs of CA from individual males was followed during this period and, at all times, the rate of synthesis was less than 8pmolh‐1 per pair, a rate similar to that observed in pregnant females. The significance of this continued synthesis of JH by male CA is unknown, although it may be related to the maintenance of general metabolic activities.

Chemical induction of mating abnormalities and spermatophore production in the Mediterranean flour moth, Ephestia kühniella

SUMMARYHexamethyl‐melamine (hemel) when injected into male Ephestia kühniella induced mating aberrations expressed as permanent copulation, sterile mating and spontaneous production of spermatophore. Permanent copulation was not caused by blockage or an elongated spermatophore column but probably caused by failure of the male reproductive organs to completely transfer the spermatophore. Spontaneous spermatophore formation was induced by both cholinesterase inhibitors and nerve stimulants, the effect of the former being more pronounced. It was not caused by stress due to poisoning since DDT even at lethal doses did not induce a response. The results suggest involvement of the nervous system in spermatophore production during a normal mating.

Cyclic Guanosine 3′,5′-monophosphate. High levels in the male accessory gland for Acheta domesticus and related crickets

Guanosine 3′,5′-monophosphate (cyclic GMP) was found in the accessory gland of reproductively mature male house crickets ( Acheta domesticus (L.)) up to the exceptionally high level of 500 pmol/mg protein (190 −4) mol/kg wet weight). The identity of cricket cyclic GMP was confirmed by enzymatic and spectral analysis. A survey of 10 closely related species of Orthoptera indicated that high levels of cyclic GMP in the accessory gland occur only in the subfamily Gryllinae, to which A. domesticus belongs. In these crickets GMP in the accessory gland increases together with protein content during two weeks after the final molt. Levels are not augmented by dissection, and are independent of the presence of sperm in the seminal vesicles and of the production of spermatophores by the gland. The function of cyclic GMP in the accessory gland is not yet understood.

Circadian control of spermatophore formation in the cricket Teleogryllus commodus Walker

The cricket Teleogryllus commodus has a circadian rhythm in spermatophore formation. A spermatophore is present 1–5 hr before the onset of stridulation under LL, DD and LD 12 : 12; it is retained during the whole stridulatory phase and disposed of within a variable time after termination of singing. Overwhelmingly one spermatophore is produced during a 24 hr-period. Severance of the abdominal nerve cord or removal of the accessory glands prevent spermatophore formation, but does not inhibit periodical stridulation; when a spermatophore is removed from a singing male, stridulation continues after a short time. Coagulation of the pars intercerebralis stops spermatophore production and singing; severance of the optic lobes rends both processes arhythmical. The rôle of the pars intercerebralis as an intermediary link between the timing-device and the effector organs is discussed.

Spermatophore formation in the pseudoscorpion Chthonius ischnocheles (Chthoniidae)

The reproduction of pseudoscorpions involves indirect sperm transfer by means of spermatophores. The spermatophores are the product of the male genital atrium. A functional interpretation of spermatophore formation in Chthonius ischnocheles is based on evidence from (a) a morphological study of the genital atrium, the associated accessory glands and the musculature (b) males sectioned during spermatophore production (c) histochemical tests on the glands and their secretions (d) biochemical analyses of one gland (posterior dorsal) and its secretion (e) the behaviour of males during this process and (f) the structure of the spermatophore.The anterior region of the genital atrium is concerned with the production of the sperm packet. The encysted sperm and the seminal fluid from the prostatic reservoir are encapsulated in a sperm packet by a secretion from two pairs of anterior glands. The posterior region of the genital atrium is responsible for the formation of the spermatophore stalk and its distal elaboration, the two lateral collars. These parts of the spermatophore arise from the fibroin secretion of the posterior dorsal gland; the shape of the spermatophore collars is correlated with their mould, the medial diverticula. In addition the lateral glands secrete a light oil which accumulates on a thickening of the spermatophore stalk proximal to the collars. This suggested that this secretion acts as a pheromone to attract females to the spermatophore since in this species males produce their spermatophores in the absence of females.

Optic glands and the state of the testis inOctopus

If the optic glands are removed from mature male octopuses, the weight of the testis and its ducts decline. Spermatophore production eventually ceases after five or six weeks. The effect of the operation is most marked in the case of large animals. If the glands are activated by removing the source of their nerve supply in the subpedunculate lobe of the suprapesophageal brain, testis and duct enlargement follows enlargement of the glands themselves ; the number of spermatophores found in the male ducts doubles within a month of the operation. Castration of the animals is not followed by a change in the weight of the male ducts, indicating that the optic gland secretion affects the state of the ducts directly rather than through the testis. Octopus vulgaris Cuvier and O. cyanea Gray were used in the experiments.

The Effects of Constant and Fluctuating Temperatures On the Production of Spermatophores and Eggs in Populations of Orchesella Cincta (Linné), (Collembola, Entomobryidae)

1. The influence of temperature on the production of eggs and spermatophores in Orchesella cincta (Linne) (Collembola), was studied at constant and fluctuating temperatures under laboratory conditions. 2. The number of spermatophores produced in a population is considered to be important for the chance of encounters between females and spermatophores and thus for the female's chance to be fertilized. The number of spermatophores is related to temperature through the instar duration. The instar duration decreases with increasing temperature, consequently the spermatophore production diminishes with increasing temperature. 3. Egg production is related to temperature through the instar frequency, and this increases with increasing temperature. 4. The production values obtained at fluctuating temperatures were about equal to that obtained at a comparable mean constant temperature.

Mating Behavior of Nemobiine Crickets: Hygronemobius, Nemobius, and Pteronemobius (Orthoptera: Gryllidae)

Pteronemobius females mount and briefly couple genitalia with males that have not yet formed spermatophores. This preliminary mounting, previously unreported for Pteronemobius and unique among Gryllidae, is prerequisite for spermatophore production in each mating sequence. The female mounts and couples genitalia with the male a second time and receives the spermatophore. The two remain coupled for an extended period while the female feeds on specialized tibial spurs of the male. This sequence is basically the same for 10 species in 3 subgenera as follows: (Allonemobius) ambitiosus species complex 3 spp., fasciatus, sparsalsus; (Neonemobius) cubensis, nr. mormonius Florida, nr. mormonius So. California; (Eunemobius carolinus, melodius. The mating pattern of Pteronemobius is interpreted as derivative from one like Nemobius sylvestris where males form and pass a small spermatophore prior to a much larger one. After each spermatophore is passed the female often feeds on a glandular area at the base of the male's tegmen. Mating in Hygronemobius alleni is no more complex than in most other gryllids: courtship is brief, a full-sized spermatophore is passed during the first mounting, and behavior after spermatophore tube insertion involves no mouthing of special glandular areas and no continued coupling.

The production, transfer and assimilation of spermatophores by Entobdella soleae, a monogenean skin parasite of the common sole.

SUMMARYIt has been shown that mating involving mutual exchange of spermatophores takes place in the skin-parasitic monogenean Entobdella soleae from Solea solea. The spermatophores are attached to the ventral surface of the body in the region of the vaginal opening and they are sucked into the vagina after mating by muscular contractions of the vaginal region.Mating takes place between young individuals with no vitellaria and between fully mature egg-laying adults but there is no evidence that self-fertilization takes place.The apparatus which manufactures the spermatophores is described and the evidence indicates that spermatozoa are injected into the jelly-like matrix of the spermatophore as the matrix is being extruded into the surrounding sea-water.I would like to thank the Director and Staff of the Laboratory of the Marine Biological Association at Plymouth for providing excellent facilities for this work and I am particularly grateful to Mr J. E. Green, who kindly fed and maintained infected soles at the Laboratory.

The functional morphology of the genitalia of the spermatophore-producing monogenean parasite Diplectanum aequans (Wagener) Diesing, with a note on the copulation of the parasite.

The genitalia of Diplectanum aequans (Wagener) Diesing are described and a functional interpretation is postulated.Spermatophores are produced from a pair of diffuse glands lying laterally amidst the vitellaria. The secretion from these glands is stored in an anterior reservoir, across the centre of which is a viscous disk which delineates two internal chambers.Each spermatophore has an elongated stalk and an ovoid head and is considered to be moulded in a muscular bulb and in the penis, prior to extrusion through the penis.The penis is composed of two concentric tubes and it has a slight hook at its distal end. The vagina has a glandular base and muscular lips. Its internal cast corresponds to the shape of the penis tip.Copulation in D. aequans is described.The occurrence and biological significance of spermatophore production in animals are discussed.I would like to acknowledge the help given to me by the Director and Staff of the Marine Biological Association Laboratory and also by the Proprietors of Cook and Sons Ltd., of Salcombe, Devon. I am most grateful to Dr J. Llewellyn for much helpful advice throughout the course of this study.The work was conducted during the tenure of a D.S.I.R. Studentship and includes the results of special studies made possible by a grant from The Browne Fund of The Royal Society.

Observations of Spermatophore Production in the Red Grasshopper Mite, Eutrombidium trigonum (Acarina: Trombidiidae)1

Studies of the biology of the red grasshopper mite, Eutrombidium trigonum (Hermann), in Missouri revealed a method of sperm transfer by the male involving the production of spermatophores. The spermatophores of this mite consist of an orange-colored sperm capsule attached to the apical portion of a thin, translucent, whitish stalk, with base embedded in the substratum. After deposition of the spermatophore, the male mites invariably perform a nuptial dance before resuming their previous exploratory or feeding activity.

The Morphology and Functions of the Reproductive Systems of Dendroctonus monticolae Hopk. (Coleoptera: Scolytidae)

AbstractThe male and female reproductive organs of the mountain pine beetle, Dendroctonus monticolae Hopk. are described, and interpretations given for functions of the parts on the basis of activity during mating, sperm transfer, egg formation and ovulation. Some morphological changes of the reproductive organs during the adult life cycle are also noted.Three pairs of accessory glands associated with spermatophore production are evident in the male beetle. One of these was previously termed the seminal vesicles. A complex musculature operates the male genital organ during copulation. The female organs have four telotrophic ovarioles with a posterior calyx region that has a possible secretory function. Evidence indicates that organs previously termed "colleterial glands" have a digestive and reabsorbing function. The bursa copulatrix may be more closely allied with the function of the accessory glands than with the mating process. Parts of the spermatheca have been more precisely defined according to function.