Relationship of food intake to the induction of plasma sex steroid-binding protein and testicular activity in immature male little brown bats (Myotis lucifugus lucifugus)

Abstract

Immature male little brown bats were aroused prematurely from their first hibernation and fed ad libitum (Group AL) or given a restricted diet (Group FR). All animals were weighed daily and the food intake of Group FR males was restricted to maintain their body weights at or near initial post-arousal values (5.3-6.8 g). The average body weights of Group AL males increased during the first week after arousal and then stabilized at a level which was 20% higher than those of Group FR males. The post-arousal induction of plasma SBP was similar in Groups FR and AL: plasma SBP activity was significantly increased 1 week after arousal and by 3 weeks had reached levels which were more than 10-fold higher than those of immature hibernating males which served as controls. Although food restriction had no effect on plasma SBP levels, it did inhibit reproductive development. Arousal-induced increases in testicular and epididymal (head/body) weights in Group FR males were less than 50% of those in Group AL males. However, histological examination of the testes revealed similar degrees of spermatogenic activation in both groups. Plasma testosterone concentrations were increased markedly in Groups FR and AL; values were generally lower in Group FR but wide individual variations were observed. Despite these elevated peripheral testosterone values, the accessory sex glands in both groups remained unstimulated.

The reproductive cycle and determination of sexual maturity in male brown long‐eared bats, Plecotus auritus (Chiroptera: Vespertilionidae)

“…The ®ndings of the present study support this proposal, since the occurrence of rudimentary testicular growth was related to body condition. A similar pattern has also been demonstrated in captive Myotis lucifugus, where puberty was delayed when food was restricted (Damassa & Gustafson, 1985). However, the appearance of testes and caudae epididymides in males having undergone spermatogenesis as yearlings did not differ from that in older males in P. auritus, and it was assumed that sexual maturity had been achieved.…”

A Novel Restraint Device to Improve Safety and Efficacy of Blood Collection During Non-Terminal Sampling of Bats

“…Typically, when anesthesia is used, an anesthetic inhalant gas (commonly Isoflurane) is delivered via nasal cone or induction chamber and maintained at 2-4% concentration using an anesthesia vaporizer and accompanying oxygen tank or oxygen concentrator. Anesthesia may be preferred by some researchers who find it easier to collect the blood sample [13,16], although it has been shown to have no significant difference in survival rates after blood sampling compared to unanesthetized bats [17]. Given that some researchers may choose to use anesthesia, the plunger (Fig.…”