Short-term cold storage of seminal samples of the golden lancehead pitviper (Bothrops insularis)

Assisted reproductive technologies such as cooling, freezing, and artificial insemination are essential in conserving genetic diversity of critically endangered reptiles like the golden lancehead pitviper (Bothrops insularis). Therefore, we examined viability of semen samples from captive golden lanceheads diluted in coconut-water based extender over a 48-h period of cooling (5°C). Semen evaluations were performed immediately after the dilution and at 6, 24, and 48 h, using computer-assisted sperm analysis and stains to assess plasma membrane and acrosomal status. Our findings showed that the extender and protocol employed here were effective in preserving golden lancehead pitviper spermatozoa for a short periods of time (48 h), allowing semen samples to be transported to distant locations for immediate use without the setbacks of cryopreservation.

Reproductive cycle and sperm storage of female coral snakes, Micrurus corallinus and Micrurus frontalis

We analyzed the hypothesis that the lack of synchronization between the mating and ovulation period of Micrurus frontalis (BRT clade) is indicative of the capacity of females to store sperm. Conversely, since these reproductive events occur in the same season for Micrurus corallinus (BRM clade), sperm storage is not expected. Thus, we analyzed the reproductive cycle of female M. corallinus and M. frontalis, and investigated the occurrence of sperm storage. Our results showed that these two species of coral snakes (clades BRM and BRT) possess different reproductive cycles. Micrurus frontalis exhibits an extensive reproductive period encompassing three seasons (summer, autumn and winter), while M. corallinus directs secondary vitellogenesis and ovulation to the hottest period of the year (spring and summer). We confirm, for the first time, the strategy of sperm storage (SSr) in females of the genus Micrurus. We observed sperm storage receptacles located in the non-glandular uterus in all seasons of the year for M. corallinus and in spring, summer and autumn in M. frontalis. Furthermore, the presence of SSr in females in the non-reproductive (post-ovulatory) period, the verification of myoid cells around the receptacles and secretion of neutral carbohydrates in the lumina of SSrs may indicates a long-term storage. The posterior infundibulum is another possible region of sperm storage by the presence of tubular ciliated gland; however, reproductive studies with other species of the genus are necessary for a better understanding of the reproductive strategies of the BRT and BRM clades.

Trophic ecology of Hemigrammus marginatus Ellis, 1911 (Characiformes, Characidae) in a conserved tropical stream

The trophic ecology of ichthyofauna in a stream can be related to the presence or absence of riparian and aquatic vegetation, and mainly resource availability. Therefore, the aim of this study was to analyse the seasonal and ontogenetic variations for the trophic ecology of Hemigrammus marginatus in the Beija-Flor stream located at the Jataí Ecological Station in the municipality of Luiz Antônio-SP, Brazil. In order to attain this objective, the data collections were carried out on a monthly basis from August, 2011 to July, 2012. Fish were collected using a trawl net and bait traps from three collection stations distributed along the Beija-Flor stream. The quality of the water was evaluated by the chemical variables: ammonia, nitrate, total nitrogen, total phosphorus, and physical temperature, dissolved oxygen, pH, turbidity and conductivity, obtained by using a Yellow Springs sonde. The collected specimens were fixed in 10% formalin in the field and were subjected to biometric measurements in the laboratory. The stomachs were weighed and transferred to 70% alcohol and the stomach contents were analysed using a stereomicroscope at the lowest possible taxonomic level. The species was considered insectivorous and the autochthonous food items were the most important during the dry season, mainly from the orders Ephemeroptera and Trichoptera, while allochthonous items from the order Hymenoptera were more important in the wet season. The young individuals' diet was based on the consumption of zooplankton, and insofar as the fish develops, there was a decrease in this item in the diet showing that the species has ontogenetic shifts in its diet. The conservation state of the Beija-Flor stream, as well as the flexibility of using food and food resources provided by aquatic macrophytes and riparian vegetation are key factors for the high abundance of the H. marginatus species.