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The long-term cryopreservation of the germplasm (spermatozoa and oocytes) of threatened species offers flexibility in their genetic management and security against disasters or outbreaks of disease that might seriously affect subpopulations. A wide range of infectious diseases can, however, be transmitted via artificial insemination, and the risk of infectious diseases being spread via manipulated germplasm needs to be carefully managed in order to avoid fertility problems in the dams and decreased survival of offspring. Furthermore, accidental introduction of exotic microorganisms into ecosystems remain a major threat. The aims of the present study were to assess the impact of diseases transmissible by sperm on the establishment of germplasm banks for the Iberian ibex, a wild mountain ungulate, and to determine the influence of the presence of these pathogens on sperm functionality. Blood and sperm samples were obtained from 52 mature ibex males legally shot in southern Spain. Sperm motility, morphological abnormalities, acrosome integrity and plasma membrane integrity were assessed for each sample to determine in vitro sperm quality. All serum samples underwent serological analysis for bovine herpes virus type I, bluetongue virus (BTV), bovine leukaemia virus, caprine arthritis-encephalitis virus, pestivirus, Brucella, Coxiella burnetii, Chlamydiophila abortus, Mycoplasma agalactiae and Borrelia burgdorferi. The highest prevalence (30.7%) was recorded for B. burgdorferi, followed by C. burnetii (13.4%). A total of 734 sperm doses containing approximately 200 × 10 spermatozoa each were frozen in straws. Forty-five straws (6.1% of the total number) came from animals seropositive for diseases listed in the Terrestrial Animal Code of the OIE for collection and processing of bovine and small ruminant semen (in this case, pestivirus and BTV). A total of 271 frozen straws (36.9% of the total of frozen straws) were provided by animals seropositive for pathogens potentially transmissible by semen not included in the above OIE code (in this case, B. burgdorferi and C. burnetii). The values of sperm variables were not affected by seropositivity for any of the pathogens transmissible by sperm. [ABSTRACT FROM AUTHOR]

The aim of this study was to induce superfetation in hares. On day 37 or 39 of pregnancy, female hares were treated with GnRH analogue and artificially inseminated with fresh semen. Ultrasonographic examination showed that pregnant females had follicles on the ovary on 37 days of pregnancy. After a few days from insemination performed during pregnancy, all females gave birth to healthy young, and one of the females inseminated on day 37 of pregnancy gave birth to two healthy young 42 days after insemination performed during pregnancy (39 days post first delivery). The same female in the next year gave birth to two healthy young 43 days after second insemination that was performed on the day 37 during pregnancy. The obtained results confirm that superfetation is possible to occur in hares. [ABSTRACT FROM AUTHOR]

Experimental insemination was performed using artificially produced low-motility sperm. A mathematical model was applied to the results of the insemination in order to clarify the relationship between sperm motility, the density of sperm and the fertilization rate of eggs. In the model, the probability of fertilization by individual spermatozoa was a function of sperm density in the insemination solution. The results showed that the probability of fertilization clearly decreased with increased sperm density, and the maximum possible fertilizing rate by increasing the sperm density was constrained by the proportion of motile sperm (% motility). The model was also applied to the results of insemination tests of cryopreserved sperm in order to evaluate the fertilizing capacity of cryopreserved sperm. It was proven that cryopreserved sperm needed a higher density to obtain the maximum fertilization rate compared with fresh sperm, and it was anticipated that the ratio of the motile inseminated cryopreserved sperm should be more than 5.0% to achieve an egg fertilization rate greater than 90%. [ABSTRACT FROM AUTHOR]

Clearnose skates, Raja eglanteria, are a common species of skate found seasonally along the Atlantic coast of North America from Cape Cod to mid-Florida and in the Gulf of Mexico from mid-Florida to eastern Texas. Clearnose skates inhabit the west central coast of Florida during winter months, when Gulf temperatures are conducive to mating and egg-laying (approximately 16°C–22°C). Specimens collected during this time will breed in captivity and, if maintained at 20°C, mated females will store sperm and continue to lay fertile eggs for up to six months. With fertile eggs available from day of laying until hatching, the first complete description of batoid elasmobranch embryonic development with a timetable has been established and is presented here. If eggs are maintained at 20°C, appearance and progression of embryonic events proceed over a reproducible timeline. The timeline has been divided into discrete time periods into which developmental events have been grouped. These include cleavage and expansion of the blastodisc (day 1–day 4), embryonic axis and neural tube formation (day 4–day 7), pharyngeal pouches and gill filament development (day 10–day 28), expansion of fins and transition from external filaments to internal gills (week 4–week 7), and epidermal pigmentation and yolk absorption (week 8–week 12). Fully formed offspring hatch after an incubation period of approximately 12 weeks (85 ± 6 days). To examine possible mechanisms of transport and storage of sperm in the reproductive tract of females following copulation, experiments resulting in the first artificial insemination for any elasmobranch fish are described. These experiments provide evidence for functional roles of the alkaline gland, whose secretions stimulate sperm motility and may enhance migration of sperm to the oviducal glands, and the clasper gland, whose secretions may provide nutrition during storage of viable sperm in the oviducal gland. [ABSTRACT FROM AUTHOR]

To apply otolith microstructure to examination of age and growth of juvenile chum salmon Oncorhynchus keta inhabiting coastal waters, formation of otolith increments was investigated for juveniles reared in a seawater aquarium and in net pens. In all otoliths examined, a distinctive check was formed at the time of sea entry of the fish. The deposition of otolith increments after the check was daily for rearing both in the aquarium (57 days) and in the net pens (26 days). Check formation associated with sea entry was also observed in otoliths of juvenile salmon collected 1 km off the coast of Shari, Hokkaido, Japan. Transmitted light observation of otoliths of those fish revealed a transition in otolith increment appearance from dark to light. Otolith Sr:Ca ratio remarkably changed from a low to a high level, coinciding with the transition in otolith appearance. It is suggested that the transition was associated with individual sea entry. This study demonstrated that the check and/or transition associated with sea entry are applicable to a benchmark for otolith increment counts of juvenile chum salmon inhabiting coastal waters. [ABSTRACT FROM AUTHOR]

The eel has long been esteemed as an important food fish in the world, especially in Japan, and has been used as an experimental fish for many fields of fish physiology. However, the decreases in eel resources have been a serious concern in recent years. The catches of glass eels as seedlings for aquaculture have shown a long-term decrease in both Europe and East Asia. To increase eel resources, the development of techniques for artificial induction of maturation and spawning and rearing their larvae have been eagerly desired. Recent progress of reproductive physiology of fish, especially mechanisms of oocyte maturation and ovulation in female and of spermatozoa maturation in male, facilitate to establish techniques for hormonal induction of maturation and spawning in sexually immature eels. With persistent effort to development of rearing techniques of larvae, we have first succeeded to produce glass eel. These applied techniques are may contribute to understand the basic reproductive physiology of the eel. [ABSTRACT FROM AUTHOR]

Presents information on the endangered species of the giant panda, while examining ways in which artificial insemination can used to protect the species. Where and when artificial insemination was applied; What has been identified as contributory to the failure of sperm-egg binding and fusion; What tests conducted showed; Analysis of the results of the tests.

Sound production during reproductive behaviour, dyadic encounters and distress situations was investigated in the callichthyid catfish Corydoras paleatus. Sounds were broad-band, pulsed, acoustic signals produced during abduction of the pectoral spines. Only males emitted trains of sounds during courting and trains of sounds of shorter duration during dyadic encounters. Several males, which are usually smaller than females, courted one gravid female without obvious cooperation or competition between them. During mating, one previously vocalizing male clasped the female's barbels with one pectoral spine and inseminated the eggs. The number of successful spawnings, days until spawning, and number of eggs laid was not related to the number of males (one, two or three) combined with one female. Males did not behave aggressively towards each other during courting or in dyadic encounters. In distress situations, when fish were hand held, both sexes and juveniles produced single sounds. The dominant frequency was negatively correlated with body size and the sound duration was positively correlated with relative length of pectoral spines (standardized to body length). This acoustical behaviour in C. paleatus differs considerably from Hoplosternum thoracatum, a representative of the callichthyine subfamily, in which vocalization was observed during territorial behaviour in males and aggressive behaviour in both sexes. This is the first report of a major difference in vocalizing behaviour within one teleost family. [ABSTRACT FROM AUTHOR]

The article reports on the controversial issues faced by the tiger breeding facility, Hengdaohezi Feline Breeding Centre, in Harbin, China. With about 800 Siberian tigers in its collection, the facility is facing media attention due to violent videos taken from its tourism programs. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) meeting, held in Hague, Netherlands on June 2007, likewise criticizes China's tiger-breeding program and threatens to reintroduce its 600 tigers into the wild. Meanwhile, scientists are also considering the genetic diversity of Siberian tigers through artificial insemination to avoid their extinction.