Carollia Perspicillata Research Articles

Formation of reticulated endoderm, Reichert's membrane, and amniogenesis in blastocysts of captive‐bred, short‐tailed fruit bats, Carollia perspicillata

Background and Methods As part of an effort to develop the short-tailed fruit bat (Carollia perspicillata) as a new animal model for the study of interstitial implantation and trophoblast-uterine interactions, early embryogenesis was examined histologically and ultrastructurally in captive-bred females at different intervals after the first appearance of spermatozoa in daily vaginal smears (day 1 postcoitum [p.c.]). Results In most of the early uterine embryos examined on days 16-18 p.c., much of the endoderm appeared as a reticulated meshwork; however, a unilocular yolk sac was formed prior to the development of any mesoderm. Early blastocysts of Carollia were also unusual in that endoderm surrounded much of the inner cell mass (ICM), Reichert's membrane continued over the dorsal side of the ICM, and basal laminalike material was observed around many of the endoderm and epiblast cells. A primordial amniotic cavity was formed between days 19 and 26 p.c. by cavitation. The first mesoderm appeared between days 23 and 26 p.c., concommitant with the development of an embryonic shield. Conclusion The unusual reticulated appearance of early endoderm in Carollia, which is reminiscent of that seen in early human blastocysts, may be attributable to constraints imposed on growth of the blastocyst by the site and mode of implantation, temporary retardation of trophoblastic invasion by the basal laminae of endometrial epithelial elements, and endodermal proliferation in anticipation of rapid yolk sac expansion. Reichert's membrane appears to play an important role in this species in tethering the ICM and embryonic shield to the developing placenta prior to the formation of significant amounts of mesoderm. Anat. Rec. 247:85-101 © 1997 Wiley-Liss, Inc.

Delayed development in the short-tailed fruit bat, Carollia perspicillata.

Pregnancy was studied in short-tailed fruit bats, Carollia perspicillata, both maintained in a captive breeding colony and collected from a reproductively synchronized wild population on the island of Trinidad. Gestation periods for captive females that successfully reared their young varied as follows: mated at a regular oestrus during their first year in captivity (105-178 days) (mean +/- SD: 145 +/- 19 days); mated at a postpartum oestrus during their first year in captivity (110-158 days) (133 +/- 16 days); mated during their second year in captivity (113-169 days) (127 +/- 12 days); females born and mated in captivity (113-159 days) (119 +/- 9 days). Most females in the last group had gestation periods of 113-119 days; this may represent the normal (nondelayed) gestation period for the species. Histological studies established that most of the observed variation in duration of gestation was due to delays occurring after the completion of implantation. It seems likely that stress, rather than age, was responsible for the prolongation of pregnancy in some animals, because this occurred less frequently in both younger and older females. There may be stressful situations in the wild (for example, lack of sufficient food or roosting sites) in which the ability to delay pregnancies would be of considerable adaptive value. Evidence was obtained that under some circumstances Carollia can extend gestation even further. Many wildcaught females successfully gave birth at 160-229 days after being isolated from breeding males in captivity. These had been captured at the time of year when, based upon subsequent histological studies of field collected specimens, most adult females should have been in early pregnancy. The field studies have also provided evidence that females in the wild population exhibit a seasonal prolongation of pregnancy.

Nitrogen and energy requirements of the short-tailed fruit bat ( Carollia perspicillata ): fruit bats are not nitrogen constrained

Nitrogen and energy requirements of the short-tailed fruit bat ( Carollia perspicillata ): fruit bats are not nitrogen constrained

Nitrogen and energy requirements of the short-tailed fruit bat (Carollia perspicillata): fruit bats are not nitrogen constrained.

Nitrogen (N) and energy (E) requirements were measured in adult Carollia perspicillata which were fed on four experimental diets. Bats ate 1.3-1.8 times their body mass.day-1 and ingested 1339.5-1941.4 kJ.kg-0.75.day-1. Despite a rapid transit time, dry matter digestibility and metabolizable E coefficient were high (83.3% and 82.4%, respectively), but true N digestibility was low (67.0%). Mass change was not correlated with E intake, indicating that bats adjusted their metabolic rate to maintain constant mass. Bats were able to maintain constant mass with digestible E intake as low as 1168.7 kJ.kg-0.75.day-1 or 58.6 kJ.. Metabolic fecal N and endogenous urinary N losses were 0.87 mg N.g-1 dry matter intake and 172.5 mg N.kg-0.75.day-1, respectively, and bats required 442 mg N.kg-0.75.day-1 (total nitrogen) or 292.8 mg N.kg-0.75.day-1 (truly digestible nitrogen) for N balance. Based on E and N requirements and digestibilities, it was calculated that non-reproductive fruit bats were able to meet their N requirements without resorting to folivory and without over-ingesting energy. It was demonstrated that low metabolic fecal requirements allowed bats to survive on low-N diets.

Evaluation of the accuracy of body temperature measurement using external radio transmitters

The facultative depression of body temperature represents an important energy strategy for small homeotherms. However, measuring body temperature under field conditions by means other than externally attached temperature-sensitive radio transmitters is problematical. We show that skin temperatures measured by external radio transmitters can accurately reflect core temperature for the bat Carollia perspicillata. We compared body and skin temperatures at three ambient temperatures (Ta; 21, 26, and 31 °C). The difference between skin and body temperature (ΔT) was linearly correlated with Ta and can be predicted by ΔT = 4.396 − 0.118Ta. We argue that external temperature-sensitive radio transmitters can provide a reliable index of core temperature and so permit the study of torpor or facultative hypothermia under field conditions.

Improved procedures for maintaining and breeding the short-tailed fruit bat (Carollia perspicillata) in a laboratory setting.

Improved methods have been developed for maintaining and breeding the neotropical short-tailed fruit bat, Carollia perspicillata, in an easily-reproduced, laboratory setting. Bipartite, all-metal cages have been designed which permit efficient, non-injurious handling of the animals. Also, a fruit-based liquid diet, which is simple and inexpensive to prepare, has been formulated from readily-available canned and powdered components. When efforts were initiated to breed wild-caught animals at 3-6 months after capture, this progressed slowly in most (but not all) cages. Breeding took place more rapidly when the bats had been in captivity for 11-24 months. Most females (122/144, 84.7%) then bred within 30 days of the introduction of a stud male, and the overall conception rate was 94.3% in those females which bred. This pattern of breeding activity, evidence that this bat is a spontaneous ovulator, and observed intervals between successive breeding periods (apparently representing much or all of non-pregnant cycles) in some individuals suggest that the cycle length in many of these bats probably falls between 20 and 30 days. Analysis of the breeding data also showed that certain patterns of breeding activity were frequently associated with a failure of females to establish ongoing pregnancies. Most laboratory-bred females (69/81) that were permitted to carry their pregnancies to term did so and successfully reared their young. The laboratory-reared young have generally exhibited excellent body condition, and many have proved to be fertile. The bats were found to exhibit a post-partum oestrus, which in nearly all cases (35/36) was fertile. The interval between the discovery of a new baby and the detection of a sperm-positive vaginal aspirate varied between 3-10 days, but most frequently was 3-6 days. Females which aborted non-term fetuses also had a post-partum oestrus with similar timing. These findings indicate that the short-tailed fruit bat, which is widely abundant in the lowland tropics of the New World, can be successfully maintained under controlled conditions, in cages of modest dimensions, for research purposes.

Secondary Sexual Dimorphism and Phylogenetic Constraints in Bats: A Multivariate Approach

We develop a method to evaluate the degree to which particular morphological characteristics contribute to multivariate group differences in general and to secondary sexual dimorphism for size and shape in particular. In addition, we recommend a correlative approach to assess the degree to which the contribution of characters to group differences is consistent in different taxa. We apply both methods to a suite of 12 cranial characters obtained from populations of 18 species of bats in five families (Emballonuridae, Noctilionidae, Phyllostomidae, Vespertilionidae, and Molossidae) from Caatinga and edaphic Cerrado biomes of northeastern Brazil. As expected, a correlation usually does not exist between profiles of the importance of characters to sexual dimorphism from the two biomes if the taxa are monomorphic with regard to sex (e.g., Vampyrops lineatus, Artibeus lituratus , and Myotis riparia ); any differences between the sexes within a biome are a result of chance. In contrast, significant correlations between profiles of importance of characters to intersexual variation in the two biomes usually exist when species are dimorphic (e.g., Anoura geoffroyi, Carollia perspicillata, Glossophaga soricina, Phyllostomus discolor, Molossus molossus , and Artibeus planirostris ). Significant constraints on the expression of sexual dimorphism exist between populations of the same species; similar suites of characters are involved in intersexual variation if dimorphism exists. Such constraints appear inoperative at higher taxonomic levels. We hypothesize that once differentiation occurs at the specific level, coadapted gene complexes and genetic dynamics associated with epistasis, pleiomorphism, and linkage disequilibrium no longer constrain dimorphism in the same fashion as in the ancestral condition.

Behavioral reactions of the bat Carollia perspicillata to abrupt changes in gravity.

As part of an ongoing survey of the behavioral responses of vertebrates to abrupt changes in gravity, we report here on the reactions of bats (Carollia perspicillata) exposed to altered gravity during parabolic aircraft flight. In microgravity, mammals typically behave as if they were upside-down and exhibit repetitive righting reflexes, which often lead to long axis rolling. Since bats, however, normally rest upside-down, we hypothesized that they would not roll in microgravity. Only one of three specimens attempted to fly during microgravity. None rolled or performed any righting maneuvers. During periods of microgravity the bats partially extended their forearms but kept their wings folded and parallel to the body. Between parabolas and occasionally during microgravity the bats groomed themselves. Both the extended limbs and autogrooming may be stress responses to the novel stimulus of altered gravity. This is the first behavioral record of Chiroptera in microgravity.

Electromotility of outer hair cells from the cochlea of the echolocating bat, Carollia perspicillata

Isolated outer hair cells (OHCs) and explants ot the organ of Corti were obtained from the cochlea of the echolocating bat, Carollia perspicillata, whose hearing range extends up to about 100 kHz. The OHCs were about 10-30 microns long and produced resting potentials between -30 to -69 mV. During stimulation with a sinusoidal extracellular voltage field (voltage gradient of 2 mV/microns) cyclic length changes were observed in isolated OHCs. The displacements were most prominent at the level of the cell nucleus and the cuticular plate. In the organ of Corti explants, the extracellular electric field induced a radial movement of the cuticular plate which was observed using video subtraction and photodiode techniques. Maximum displacements of about 0.3-0.8 microns were elicited by stimulus frequencies below 100 Hz. The displacement amplitude decreased towards the noise level of about 10-30 nm for stimulus frequencies between 100-500 Hz, both in apical and basal explants. This compares well with data from the guinea pig, where OHC motility induced by extracellular electrical stimulation exhibits a low pass characteristic with a corner frequency below 1 kHz. The data indicate that fast OHC movements presumably are quite small at ultrasonic frequencies and it remains to be solved how they participate in amplifying and sharpening cochlear responses in vivo.

Further characterization of the pituitary‐adrenocortical responses to stress in Chiroptera

Previous studies on bats from this laboratory have revealed the presence of exceptionally high circulating levels of glucocorticoids in two species of the sub-order Megachiroptera. In the present study, the following questions were asked: (1) what effect does the routine handling and examination of captive bats have on the activity of their hypothalamic-pituitary-adrenocortical (HPA) axis?; (2) are the unusually high plasma levels of cortisol and corticosterone found in Pteropus hypomelanus associated with high levels of circulating adrenocorticotropic hormone (ACTH)?; (3) are there diurnal changes in stress responsivity in this species?; and (4) how do levels of glucocorticoids in P. hypomelanus compare with those found in other species of Chiroptera (both micro and megachiropteran species)? Of five species examined, P. hypomelanus had slightly higher total glucocorticoid levels than P. pumulis, but approximately 8-fold higher levels than in three species of Microchiroptera (Artibeus jamaicensis, Carollia perspicillata, and Myotis lucifigus). There was a pronounced diurnal rhythm in glucocorticoid levels in one species (M. lucifigus) for which this was determined. A 1-h period of restraint stress increased glucose and glucocorticoid levels in P. pumulis, and also increased ACTH and glucocorticoids in P. hypomelanus. Fifteen minutes of routine handling (weighting, measuring, etc.) elicited a significant rise in plasma glucocorticoids in P. hypomelanus to combined peak (cortisol plus corticosterone) levels of over 1,000 ng/ml (100 micrograms%). There was no significant difference in the response to handling in bats tested in the morning or evening. Basal ACTH levels as detected by radioimmunoassay were low in P. hypomelanus, in spite of high steroid levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Dispersão de sementes de Vismia cayennensis (Jacq.) Pers. (Guttiferae) por morcegos na região de Manaus, Amazonas

Estudou-se o comportamento alimentar de morcegos e o seu papel na dispersão de sementes de Vismia cayennensis na região de Manaus, Amazonas. As características da planta e dos frutos correspondem à síndrome de quiropterocoria. Cinco espécies de morcegos filostomídeos se alimentaram dos frutos: Sturnira lilium, Sturnira tildae, Artibeus concolor, Carollia perspicillata e Rhinophylla pumilio. Aparentemente, há uma relação entre o comportamento de forrageamento em grupos e a maior disponibilidade de frutos na primeira parte da noite. O comportamento alimentar foi semelhante para todas as espécies de morcegos, variando em função do modo de apresentação dos frutos. Os testes de germinação e os padrões de distribuição das plantas indicam que morcegos são os dispersores efetivos de V. cayennensis.

The postnatal development of frequency-place code and tuning characteristics in the auditory midbrain of the phyllostomid bat, Carollia perspicillata

This report describes the postnatal development of hearing range, auditory sensitivity and tonotopy within the inferior colliculus (1C) of a mammal specialized for ultrasonic hearing. The experimental animal, Carollia perspicillata, has an adult hearing range of 7–110 kHz (characteristic frequencies) but lack any significant overrepresentation of a limited frequency hand as known for rhinolophoid bats and Pteronotus. The audiogram of the newborn Carollia includes characteristic frequencies from 8 to 76 kHz, which is about 65% of the adult hearing range. As in adults, low frequencies are represented in the dorsolateral portion of the 1C. However, at birth the ventromedial 1C is non-responsive to acoustic stimulation up to intensities of 90 dB SPL. During development there is a progressive conversion of non-responsive 1C areas into acoustically responsive slabs with characteristic frequencies above 76 kHz along the dorsolateral to ventromedial (low-to-high frequency) 1C axis. This development is superimposed by a non-uniform shift of characteristic frequency: a decrease of CFs in dorsolateral regions, and an increase of CFs in ventromedial areas. The results suggest a bidirectional shift of frequency representation along the cochlear tonotopic axis.

Histochemical and myosin composition of vampire bat (Desmodus rotundus) pectoralis muscle targets a unique locomotory niche.

The vampire bat pectoralis muscle contains at least four fiber types distributed in a nonhomogeneous pattern. One of these fiber types, here termed IIe, can be elucidated only by adenosine triphosphatase (ATPase) histochemistry combined with reactions against antifast and antislow myosin antibodies. The histochemical and immunohistochemical observations indicate a well-developed specialization of function within specific regions of the muscle. In parallel, analyses of native myosin isoforms and myosin heavy chain isoforms indicate two points. First, the histochemical "type IIe" fiber is predominant in cranial portions of the muscle, and myosin extracted from these regions exhibits a unique electrophoretic mobility not observed in the myosin isoforms of more traditional laboratory mammals. Second, the type I fibers are confined to the pectoralis abdominalis muscle and a small adjacent region of the caudal part of the pectoralis. This pattern of type I fiber distribution is considered a derived character state compared to muscle histochemical phenotype and isoform composition in the pectoralis muscles of other phyllostomids we have studied (Artibeus jamaicensis, Artibeus lituratus, Carollia perspicillata). We relate this to the unique locomotory needs of the common vampire bat, Desmodus rotundus.

Murcielagos del norte de Antioquia (Colombia)

This study reports the presence of 30 species of bats collected at different altitudes in the north of Antioquia Department, Colombia. The species captured belong to five families, six subfamilies and 18 genera. All listed pertain to the suborder Microchiroptera, order Chiroptera and the mayority to the family Phyllostomidae. The most abundant species were Artibeus lituratus, Carollia perspicillata and Molossus molossus. Six tipes of diets were catalogued for the captured specimens. Most abundant were fruit eaters, followed by insectivorous and nectivorous bats. Very few fish eaters, carnivors or omnivors were found. No vampires were captured, although their presence was noted in the typical bite marks seen on cows and horses of the region.

Dietary Overlap in Frugivorous and Insectivorous Bats from Edaphic Cerrado Habitats of Brazil

Previous studies on size patterns within frugivorous and insectivorous bat guilds from north-eastern Brazil suggest significant ecological separation of species. Nonetheless, recent simulation studies indicate that stochastic processes alone, rather than competition or coevolution, account for the morphological structure of these communities. To evaluate the dietary consequences of observed morphological structure, monthly samples of bats were collected (September 1976–May 1978) within edaphic Cerrado habitats on the Chapada do Araripe in northeastern Brazil. For each of the 11 most common species, stomach contents were identified, and the diets characterized for wet and dry seasons. Nonparametric statistical analyses of dietary constituents revealed two non-overlapping groups of frugivores based upon a posteriori contrasts: those that specialize on one food source, Vismia sp. ( Carollia perspicillata, Artibeus planirostris, A. lituratus ), and those that are more generalistic in their feeding habits ( Glossophaga soricina, Sturnira lilium, Vampyrops lineatus ). Statistical analyses of insectivorous species produced a homogeneous group ( Anoura geoffroyi, Phyllostomus discolor, P. hastatus, Molossus molossus ) based on classification of diet into hard-bodied versus soft-bodied insects. Like the ecomorphological assessments of community structure, our results failed to detect pervasive dietary differences among species that are related to size considerations.

High frequency distortion products from the ears of two bat species, Megaderma lyra and Carollia perspicillata

In two echolocating bat species, Megaderma lyra and Carollia perspicillata 2f1−f2 distortion products were measured acoustically in the outer ear canal for f1 frequencies between 5 and 95 kHz in an attempt to study nonlinear cochlear processes at high frequencies. Similar to other mammals, the input/output (I/O) functions of 2f1−f2 show non-monotonicities and notches at f1 levels between 40–70 dB SPL. The slope of the initial rise of the 2f1−f2 I/O functions increased with ft frequency from 0.73 (5 kHz) to 1.41 (95 kHz) in Megaderma and from 0.66 (7.5 kHz) to 1.47 (95 kHz) in Carollia. With increasing f1 frequency the optimum frequency ratio f2/f1 in order to evoke maximum distortion level decreases from 1.18 (5 kHz) to 1.09 (95 kHz) in Megaderma and from 1.21 (75 kHz) to 1.11 (95 kHz) in Carollia. This is taken as indication of a general increase of the quality of tuning of the distortion generating mechanism with frequency. The f1 levels that were sufficient to elicit distortion levels of − 10 dB SPL were used to construct iso-distortion threshold curves which lay on average 37.2 dB (Megaderma) and 33.9 dB (Carollia) above the neuronal threshold curves [Rübsamen et al., J. Comp. Physiol. A 163 (1988); Sterbing et al., Proc. 18th Göttingen Neurobiol. Conf. Thieme Verlag, Stuttgart (1990)] and roughly parallel these. Highest distortion levels (40–50 dB SPL with f1 levels of 80 dB SPL) and lowest distortion thresholds were measured in the f1 frequency range of 10–30 kHz (Megaderma) and 15–30 kHz (Carollia). For both bat species these respective frequency ranges correlate with broad minima in the neuronal audiogram. Thus in these animals distortion measurement can be used as noninvasive means to assess relative hearing threshold. Systemic application of salicylate (100–400 mg/kg) which is known to block outer hair cell (OHC) motility (Shehata et al., 1991) reduced the level of distortion by up to 25 dB (ft frequency: 20 kHz) and up to 36 dB (f1 frequency: 70 kHz).

Brazilian students in the developed countries

Aggressive behaviours have an important impact on the social organization of animals and on the social status of individuals, especially in gregarious species. Agonistic interactions between territory holders are essential to set and reinforce territorial borders. Additionally, agonistic displays are used to demonstrate ownership of a territorial site and may indicate social status of the signaller. Between neighbouring territory owners, dynamic borders require frequent interactions. In daily repeated aggressive encounters, ritualization can help to avoid the need for serious fights and their costly consequences. In the bat Carollia perspicillata, a gregarious frugivore with resource defence polygyny, males defend territories at valuable roosting sites for females. Working with a captive bat colony of about 400 individuals, housed under seminatural conditions in a tropical zoo, we found that males defended territories aggressively by the use of a succession of displays forming a ritualized structure. Simultaneously, males used three different vocalization types during aggressive displays, namely down-sweeps, warbles and aggressive trills. A statistical analysis of 58 aggressive trills from five adult males showed that they contained sufficient variation to encode an individual signature. Using a habituation–dishabituation paradigm playback experiment, we found that males could discriminate between vocalizing males based on aggressive calls alone. Such discrimination is probably useful for distinguishing between neighbouring territory owners and more unfamiliar intruders, and thus allows for an economical response.

Olfactory discrimination ability in short-tailed fruit bat,carollia perspicillata (Chiroptera: Phyllostomatidae)

The olfactory discrimination ability in a fruit-eating bat,Carollia perspicillata, was investigated. In a food-rewarded flight training procedure, four animals were taught to choose one of two odors simultaneously presented in a three-choice apparatus.Carollia chose the odor of ripe banana over that of unripe banana in a spontaneous choice test. With the same method, the bats significantly preferred undiluted banana odor compared to a dilution of 1∶ 10, but did not express a preference between undiluted and 1∶5 dilutions of ripe banana. In a series of reinforced choice tests, the positive stimulus (CS +) was the standardized odor of natural ripe banana. Prominent components of this complex odor were used as CS -, first in monomolecular form and later in combinations (odor cocktails) of increasing similarity to banana odor. In all these tests the bats easily discriminated the natural food odor from the artificial ones. Even a gas Chromatographic congruity of 57% between the major components of natural banana odor and an odor cocktail caused no impairment of the olfactory performance. The olfactory discrimination ability ofCarollia perspicillata supports the assumption that echolocating, frugivorous bats may use their sense of smell to find and select their food.

Animal Sonar: Processes and Performance

<i>Animal Sonar: Processes and Performance</i>

Olfactory sensitivity to food odor components in the short-tailed fruit bat, Carollia perspicillata (phyllostomatidae, chiroptera)

The absolute olfactory sensitivity in a frui-teating bat, Carollia perspicillata, was investigated. Eighteen monomolecular food odor components from 3 substance classes were tested using a sniff rate analysis method. Detection thresholds (Table 1) ranged from 3.6 · 1013 to 2.7 · 1010 molecules/cm3 air. Interindividual variation (N = 4) for a substance did not exceed one order of magnitude. Significant correlations between olfactory performance and carbon chain length of the odor molecule were found for two substance classes: Sensitivity to the aliphatic iso-alcohols increased linearly from C2 to C5, and a nonlinear correlation was found for the acetic esters, with the C4- and C7-forms being clearly better perceived than the other homologues. In acetic esters, the sensitivity for the n-forms of the molecule was significantly higher than for the iso-forms. No such correlation between stereo-isomers and olfactory perception was found for the n- and iso-forms of carbon acids and aliphatic alcohols. Fruit-typical odor components like ethyl butyrate (5.4 · 1010), n-pentyl acetate (2.8 · 1010), or linalool (1.8 · 1011 molecules/cm3 air) were the most effective among all compounds tested, suggesting that the nutritional specialization of the bat may be associated with a specific spectrum of olfactory sensitivity.