Emballonurid Bats Research Articles

Effects of the temperature on activity patterns and torpor in Saccolaimus saccolaimus in Bangladesh with notes on its morphometrics and roosting behaviour

Saccolaimus saccolaimus is one of the six Emballonurid bats and the only species from the genus Saccolaimus that occurs in South and Southeast Asia. This species utilizes tree hollows, damaged palm trees, and occasionally artificial structures as roosts. We recorded a total of 22 bats from 10 colonies located at two dormitories in Jahangirnagar University (JU) in a sub-urban setting in central Bangladesh. The number of bats per colony varied between 1-9 individuals, with an average of four bats per colony. We found that the colonies of S. saccolaimus emerged from roosting sites when the temperature was 22.5°C or higher. The highest bat activity was recorded in September (79.66 mins) when the air temperature was 27.66°C, and the lowest was in January (47.01 mins) when the air temperature was 17.46°C. We observed variations in bat activity in different months, and bat activity was strongly correlated (R-square = 0.52) with air temperature. The most extended torpor period for the colonies was recorded for 27 days. The mean weight for male S. saccolaimus in JU was 41.66 ± 0.29 (41.46-42) g, whereas for females was 45.32 ± 3.08 (43.14- 47.5) g. Although some variation was observed in the morphological measurements, the morphometric analysis indicated no significant differences between specimens from Bangladesh and the neighbouring countries. Further research is needed to understand various ecological aspects of S. saccolaimus in Bangladesh. Therefore, to do so, the existing colonies on JU campus should be extensively monitored.

Histological Investigation of Cyclic Variation in Secretory Activity of Seminal Vesicles in Emballonurid Bat, Taphozous kacchensis (Dobson)

The present study describes the cyclical changes in the secretory activity of the seminal vesicle in the emballonurid bat, Taphozous kacchensis. The secretory activity in the seminal vesicles during the quiescence cycle was not well marked in T. kacchensis. During the sexually quiescent period (May to August), seminal vesicles were regressed, the tubules were lined by cuboidal to low columnar epithelial cells with round to elongated darkly stained basally to centrally placed nuclei. Cytoplasm was basophilic containing fine or coarse secretory granules in the cytoplasm. The lumina of the tubules were devoid of secretion. During the pre-breeding (September to January) period, the tubules were enlarged and were lined by tall columnar epithelial cells with large spherical basally situated nucleus. The secretory blebs were seen arising from the apical surface of the cells and were seen releasing into the lumen. Lumina of the tubules were filled with homogenous eosinophilic secretion. During the breeding period (February to March), the seminal vesicle showed hypertrophy resulting in the increase in the tubular diameter as compared to that of quiescent period. The epithelial lining of the tubules was cuboidal with centrally placed nuclei. The tubular lumina were full of homogenous secretion during active pre-breeding and breeding period as the secretory material released into the lumen by both apocrine and merocrine modes. Regressive changes in the seminal vesicle were evident from April. The tubules showed gradual hypotrophy as the quiescent period approaches in May.

Northern distributional extensions of Peropteryx leucoptera and Peropteryx pallidoptera (Chiroptera: Emballonuridae) from Vichada, Colombia

The White-winged Dog-like Bat (Peropteryx leucoptera) and the Pale-winged Dog-like Bat (Peropteryx pallidoptera) are distinguished from the other emballonurid bats because they have white or translucent wings. Their distribution and biology are poorly known due to they are no captured in traditional bat inventories using mist nets. In this contribution, we extend the known distribution of P. leucoptera 260 km NE and P. pallidoptera 290 km NE. Our records are from three specimens collected in a mammal assessment at the riparian corridor of the river Meta in the Vichada department. This locality is the northern limit of the distributional range of both species. We highlight the need to continue the fieldwork on mammals inventories with specimen collections through the Colombian Llanos. We call attention to the importance of horizontal rotten logs as roost of P. leucoptera and other little known neotropical bats.

Karyotypic and phylogeographic analyses of Cormura brevirostris (Chiroptera, Emballonuridae)

Cormura brevirostris is a rare and poorly known species of emballonurid bat that occurs in Central America and South America across the Amazonian region. Previous work showed that karyotypes of C. brevirostris from Colombia, Suriname, and the Brazilian Amazon presented 2n = 22 and FN = 40, although small differences in chromosome composition have been observed among these karyotypes. Phylogenetic studies using nuclear and mitochondrial markers also showed differences between Central and South American C. brevirostris individuals. We describe the karyotype of an adult male C. brevirostris from the Brazilian Amazon and compare it to other karyotypes reported for this species. We also investigate phylogenetic relationships within this species using 2 mitochondrial and 1 nuclear gene. Morphological characters and measurements of the Brazilian specimen matched those described for C. brevirostris. The karyotype displayed a C-banding pattern similar to those described for C. brevirostris from other localities. Phylogenetic analyses confirmed the monophyly of Cormura, but each marker showed a different relationship. Karyological data showing more than 1 lineage and deep intraspecific mitochondrial lineages suggest that this taxon could be a species complex, requiring additional taxonomic studies to elucidate species limits and phylogenetic relationships within the genus Cormura.

Emballonuridae Gervais, 1855 (Chiroptera) of Reserva Biológica de Saltinho (Atlantic Forest), in Brazil, revealed by echolocation

Seventeen species of emballonurid bats are known in Brazil, but their distribution is often determined by patchy records. However, due to almost species-specific calls, echolocation can help to refine the distribution of emballonurids. Here we use acoustic samplings to assess and complement the list of emballonurids of Reserva Biológica Saltinho, an important Atlantic Forest remnant in Pernambuco state, Northeastern Brazil. We positively matched calls of Saccopteryx bilineata (Temminck, 1838) that was foraging along forest edges. However, a series of calls significantly different from those emitted by S. bilineata indicate the presence of a second Saccopteryx sonotype in the area. The lower frequencies in this sonotype presumably came from a larger species, indicating the possible existence of an undescribed cryptic species of Saccopteryx. We also detected Centronycteris maximiliani (Fischer, 1829), recorded 35 years after its first record in Pernambuco, and an undetermined species of Peropteryx Peters, 1867. Our data proved that echolocation is a very useful technique for inventorying poorly known and hard-to-capture emballonurid species, with the potential to reveal the cryptic richness.

On the roosting and mating of Saccolaimus saccolaimus (Chiroptera) in Bangladesh

Saccolaimus saccolaimus is an emballonurid bat and the only species from the genus Saccolaimus that occurs in South and Southeast Asia. It is medium-sized (FA 63.0–68.0 mm) and has a body covered with chocolate brown to black fur with whitish speckles on the dorsum. The muzzle of the bat is nearly hairless, ears are of moderate size and fluted, the tragus faces outwards, the tail projects a little from the uropatagium and is stout, and a distinctive feature is the gular sac which is prominent in males and less so in females. A foul odour is often associated with these bats. Khan (2001) recorded 31 species of bats from Bangladesh including S. saccolaimus but did not specify distribution. Srinivasulu & Srinivasulu (2012), however, report 37 species from Bangladesh. No account of roosting or mating behaviour of this species has come from Bangladesh although it has been listed as occurring in the country. Here we report our observations of roosting and mating behaviour in S. saccolaimus, a first for the country.

Mamíferos del departamento del Chocó, depositados en las tres colecciones científicas más importantes de los Estados Unidos

Objective: To complete the available information on biodiversity of the department of Choco. Methods: We analyzed museological records of Chocoan specimens deposited in the three main collections of the United States: American Museum of Natural History de Nueva York (AMNH, 39 spp/127 records); Field Museum of Natural History de Chicago (FMNH, 53 spp/374 records); y el United State National Museum of the Smithsonian Institution de Washington DC (USNM, 19 spp/65 records). To evaluate the importance of of the analyzed material we contrasted the recovered records with Chocoan records deposited at the collection of the Instituto de Ciencias Naturales of the Universidad Nacional de Colombia (ICN, 52 spp/721 registros). Results: As product of our analyses we generated a database of 566 records representing a total of 82 Chocoan mammalian species deposited in scientific collections of the United States. The analyzed records require an urgent revision of their taxonomic status, in order to make them a useful source of information for local decision makers. We highlight the presence of the Colombian endemic primate Saguinus oedipus, for department of Choco, supported by material deposited at the AMNH. In the same manner we report the presence of the emballonurid bat Cormura brevirostris, and the slot Choloepus didactylus, that if taxonomically confirmed will represent significant distribution extensions and first confirmed records in collections of these taxa for the department. We also highlight the records of the nectarivorous bat Hylonycteris underwoodi and the coati Nasua narica candace, both species known from Central America and potentially present in the department. Finally, called our attention the presence of a mandible of the manatee (Trichechus manatus) from the municipio of Unguia deposited at the FMNH; this represents the only museum voucher material of the species from this portion of the Colombian territory.

Dynamics of the echolocation beam during prey pursuit in aerial hawking bats

In the evolutionary arms race between prey and predator, measures and countermeasures continuously evolve to increase survival on both sides. Bats and moths are prime examples. When exposed to intense ultrasound, eared moths perform dramatic escape behaviors. Vespertilionid and rhinolophid bats broaden their echolocation beam in the final stage of pursuit, presumably as a countermeasure to keep evading moths within their "acoustic field of view." In this study, we investigated if dynamic beam broadening is a general property of echolocation when catching moving prey. We recorded three species of emballonurid bats, Saccopteryx bilineata, Saccopteryx leptura, and Rhynchonycteris naso, catching airborne insects in the field. The study shows that S. bilineata and S. leptura maintain a constant beam shape during the entire prey pursuit, whereas R. naso broadens the beam by lowering the peak call frequency from 100 kHz during search and approach to 67 kHz in the buzz. Surprisingly, both Saccopteryx bats emit calls with very high energy throughout the pursuit, up to 60 times more than R. naso and Myotis daubentonii (a similar sized vespertilionid), providing them with as much, or more, peripheral "vision" than the vespertilionids, but ensonifying objects far ahead suggesting more clutter. Thus, beam broadening is not a fundamental property of the echolocation system. However, based on the results, we hypothesize that increased peripheral detection is crucial to all aerial hawking bats in the final stages of prey pursuit and speculate that beam broadening is a feature characterizing more advanced echolocation.

Spatiotemporal expression patterns of macrophage migration inhibitory factor (MIF) and its receptor CD74 in mink placenta

Bats are a highly successful, widely distributed group, with considerable variation in placental structure. The Egyptian slit-faced bat Nycteris thebaica is a member of one of the few families with previously undescribed placentation. It was found that, although the interhemal type of the Nycteris placenta is endotheliochorial with a single layer of cytotrophoblast, the arborizing pattern of the maternal vessels and especially the extraordinary major placental artery differs from the placenta of the emballonurid bats to which this family is considered to be most closely related. The major placental artery providing maternal blood to the vessels of the placental disk has a highly glycosylated matrix surrounded by two-layered folds of trophoblast, forming an apparently rigid structure of unique morphology. The yolk sac is collapsed, with hypertrophied endodermal and mesothelial cells similar to many other bat species. The paraplacenta is extensive with abundant fetal vessels underlying cytotrophoblast and syncytial trophoblast layers, fronting on an endometrium that largely lacks uterine epithelial cells but has large decidual cells and is poorly vascularized. The placenta of Nycteris lacks a hemophagous region, unlike the emballonurid bats Taphozous and Saccopteryx. Although the latter two species have similar placentas, the placental structure of Nycteris does little to relate it to the other family within the Emballonuroidea. Shared and divergent reproductive characters are discussed in relationship to bat phylogenetic relationships.

Emballonurid bats from Colombia: Annotated checklist, distribution, and biogeography

Introduction: Genetic data hypothetically place the origin of the most recent common ancestor of the subfamily Emballonurinae in Africa, suggesting a dispersal event from Africa to South America during the Oligocene (30 Ma), and a subsequent allopatric radiation in the New World. Emballonurid genera exist in Central America where, to date, only one event of diversification has been documented for Balantiopteryx before the completion of the Isthmus of Panama land connection in the Pliocene.Methods: Emballonurid bats constitutes an important element of the bat fauna in Colombia. Herein, museum voucher specimens were used as primary source to generate a checklist of emballonurid bats from Colombia. In addition, selected museum voucher specimens were analyzed to verify their identifications. The checklist is accompanied by references as well as models of potential distribution for each Colombian emballonurid species. These distribution maps were used to investigate the affinities, in species composition, among Colombian ecoregions as outlined by Hernández-Camacho et al. (1992), and to determine emballonurid richness distribution in Colombia and the relationship between environmental variables and patterns of species richness in this group of bats in the country.Results: We report 16 confirmed emballonurid bat species for Colombia and three species potentially present in the country, for a total of 19 species representing the eight recognized Neotropical emballonurid genera. At 16 known species, Colombia has the second greatest number of Neotropical emballonurid bats after Brazil (17 spp.).Discussion and conclusion: The checklist presented herein is accompanied by 11 taxonomic and distributional comments explaining recent changes in taxonomy, species distribution rearrangements, as well as clarifications and a refinement of the previous records for Colombia. In addition, Geographic Information System (GIS) models of potential distribution were created for all confirmed species in Colombia, and species richness patterns were analyzed. Finally, in a Parsimony Analysis of Endemism was performed for Colombian emballonurids we found that diversity within this group of bats in geographically subdivided in Colombia into four main regions including: The Biogeographic Chocó; the Magdalena Valley; The Orinoquia; and the Guianan-Amazon region.Key words: Chiropterans, Parsimony Analysis of Endemism, sheath-tailed bats, sac-wing bats, distribution maps.

Dispersal and social organization in the Neotropical Grey sac-winged bat Balantiopteryx plicata

Recent evidence suggests that tropical bats may frequently depart from the predominant mammalian male-biased dispersal pattern. So far, two emballonurid bat species that are closely related to our study species (Grey sac-winged bat, Balantiopteryx plicata) have been found to exhibit exceptional female-biased dispersal that is in accordance with father–daughter inbreeding avoidance. In contrast, using a combination of long-term behavioral observations of banded bats and DNA sequencing of the mitochondrial d-loop, our results suggest that B. plicata is the first Neotropical emballonurid with female philopatry and frequent male dispersal. However, just like in the other emballonurids, the age of females at first conception fell below the tenure of males. Thus, philopatric B. plicata females might face a father–daughter inbreeding risk if mating with males from their roosts. Such risk could be circumvented if mating occurs outside the nursing roost, e.g., in male mating aggregations. In contrast to other Neotropical emballonurid bats, the Grey sac-winged bat forms colonies with a greatly male-biased sex ratio (only 5 and 21 % females). Males of such colonies showed high roost fidelity and the sex ratio did not change throughout the year and for up to many years, suggesting an important role in mating. We conclude that studying the diverse mating and dispersal patterns of Neotropical emballonurids shows great potential to enlarge our understanding on how the proposed ultimate causes (i.e., avoidance of inbreeding and local competition between kin) affect the evolution of sex-biased dispersal.

Echolocation beam shape in emballonurid bats, Saccopteryx bilineata and Cormura brevirostris

The shape of the sonar beam plays a crucial role in how echolocating bats perceive their surroundings. Signal design may thus be adapted to optimize beam shape to a given context. Studies suggest that this is indeed true for vespertilionid bats, but little is known from the remaining 16 families of echolocating bats. We investigated the echolocation beam shape of two species of emballonurid bats, Cormura brevirostris and Saccopteryx bilineata, while they navigated a large outdoor flight cage on Barro Colorado Island, Panama. C. brevirostris emitted more directional signals than did S. bilineata. The difference in directionality was due to a markedly different energy distribution in the calls. C. brevirostris emitted two call types, a multiharmonic shallowly frequency-modulated call and a multiharmonic sweep, both with most energy in the fifth harmonic around 68 kHz. S. bilineata emitted only one call type, multiharmonic shallowly frequency-modulated calls with most energy in the second harmonic (~46 kHz). When comparing same harmonic number, the directionality of the calls of the two bat species was nearly identical. However, the difference in energy distribution in the calls made the signals emitted by C. brevirostris more directional overall than those emitted by S. bilineata. We hypothesize that the upward shift in frequency exhibited by C. brevirostris serves to increase directionality, in order to generate a less cluttered auditory scene. The study indicates that emballonurid bats are forced to adjust their relative harmonic energy instead of adjusting the fundamental frequency, as the vespertilionids do, presumably due to a less flexible sound production.

First occurrence of the rare emballonurid bat Cyttarops alecto (Thomas, 1913) in Peru—Only hard to find or truly rare?

The short-eared bat Cyttarops alecto (Emballonuridae) is a rare onotypic genus and poorly known throughout its distribution Hood and Gardner, 2008). This species inhabits lowland forests t elevations not higher than 500 meters from Nicaragua through osta Rica, Guyana, Suriname, French Guyana to northern Brazil nd southern Colombia (Simmons, 2005; Hood and Gardner, 2008; imetal., 2008; Lim,2009).Oneadditional recordofCyttaropsalecto n Palmeirante, Brazil (Nunes et al., 2006), currently represents the outhernmost known limit of this species (Fig. 1). Information on the natural history of this species is also scarce. ost capture localities are representedbysingle individuals, except or a few places in Costa Rica where Cyttarops alecto was found n small groups of up to twelve individuals beneath coconut alm fronds (Starrett and de la Torre, 1964; Starrett, 1972; Reid nd Langtimm, 1993; Hood and Gardner, 2008). Stomach conents of the specimens went along with the insectivorous foraging ehaviour (Starrett and de la Torre, 1964; Starrett, 1972; Nunes et l., 2006). At present, C. alecto is considered absent from Peru (Simmons, 005; Hood and Gardner, 2008; Pacheco et al., 2009). Here, we ocument the first record of C. alecto from Peru, present informaion on morphological variation and a note on the ecology of this pecies.

Characterization of eight novel microsatellite markers for the neotropical bat Rhynchonycteris naso and cross-species utility

Neotropical emballonurid bats are known to exhibit an exceptional diversity in social systems and dispersal strategies. Here we report the isolation of eight new microsatellite markers which will be employed to investigate ultimate causes and consequences of sex-biased dispersal by use of paternity, relatedness and population structure analyses. Novel microsatellite markers developed for the species Rhynchonycteris naso turned out to be highly polymorphic. Number of alleles ranged from seven to 31 alleles per locus and expected heterozygosities ranged from 0.74 to 0.95. Seven loci were autosomal and one locus appeared to be situated on the X-Chromosome. Cross-species amplification in four species was more successful in more closely related than in more distantly related genera of neotropical emballonurids. Together with other eleven microsatellites initially isolated for Saccopteryx bilineata, we now posses powerful tools for studying species of the two bat genera, Saccopteryx and Rhynchonycteris.

Placentation in the Egyptian Slit-faced Bat Nycteris thebaica (Chiroptera: Nycteridae)

Bats are a highly successful, widely distributed group, with considerable variation in placental structure. The Egyptian slit-faced bat Nycteris thebaica is a member of one of the few families with previously undescribed placentation. It was found that, although the interhemal type of the Nycteris placenta is endotheliochorial with a single layer of cytotrophoblast, the arborizing pattern of the maternal vessels and especially the extraordinary major placental artery differs from the placenta of the emballonurid bats to which this family is considered to be most closely related. The major placental artery providing maternal blood to the vessels of the placental disk has a highly glycosylated matrix surrounded by two-layered folds of trophoblast, forming an apparently rigid structure of unique morphology. The yolk sac is collapsed, with hypertrophied endodermal and mesothelial cells similar to many other bat species. The paraplacenta is extensive with abundant fetal vessels underlying cytotrophoblast and syncytial trophoblast layers, fronting on an endometrium that largely lacks uterine epithelial cells but has large decidual cells and is poorly vascularized. The placenta of Nycteris lacks a hemophagous region, unlike the emballonurid bats Taphozous and Saccopteryx. Although the latter two species have similar placentas, the placental structure of Nycteris does little to relate it to the other family within the Emballonuroidea. Shared and divergent reproductive characters are discussed in relationship to bat phylogenetic relationships.

Flying-fox (Megachiroptera: Pteropodidae) flight altitudes determined via an unusual sampling method: aircraft strikes in Australia

The nocturnal behaviour of bats makes it difficult to determine their foraging habits at night, especially in regards to the height or altitude at which they fly. This is particularly true for the larger flying foxes that can travel up to 40 km in a single night(Spen cer et al., 1991; Parsons et al., 2006). Despite the value of such information for many aspects of the foraging ecology and ecophysiology of bats, gathering information on the flight altitudes used by bats remains a challenge that has led to the use of inventive sampling techniques. Active radar systems monitoring aircraft movements have detected the Mexican free-tailed bat (Tadarida brasiliensis) flying at altitudes of over 3,000 m (10,000 feet) (Williams et al., 1973), while helium filled kite balloons in combination with bat echolocation detection devices have identified molossid and emballonurid bats foraging at heights of almost 600 m (1968.5 feet) (Fenton and Griffin, 1997). The diurnal Sa moan flying fox, Pteropus samoensis, has been observed soaring on thermal updrafts (Rich mond et al., 1998; Lindhe Norberg et al., 2000; Thomson et al., 2002), but unfortunately knowledge on the actual flying altitude of this or any other pteropodid species remains unknown.

Historical biogeography of New World emballonurid bats (tribe Diclidurini): taxon pulse diversification

AbstractAim To reconstruct the biogeographical history of New World emballonurid bats (tribe Diclidurini). Although bats are the second most species‐rich order of mammals, they have not contributed substantially to our understanding of the historical biogeography of mammals in the Neotropics because of a poor fossil record. In addition, being the only group of mammals that fly, bats typically have large distributions with relatively few species endemic to restricted areas that are amenable to vicariant biogeographical approaches.Location Central and South America.Methods Phylogenetic analysis for comparing trees (PACT) is a new algorithm that incorporates all spatial information from taxon area cladograms into a general area cladogram. There were nine biogeographical areas identified in Central and South America for New World emballonurid bats. Molecular dating was used to incorporate the temporal aspect of historical biogeography. This method was compared with dispersal–vicariance analysis (DIVA), which assumes vicariance as the default mode of speciation.Results Of the 45 speciation events in a fully resolved phylogeny, eight that were hypothesized by DIVA as vicariance were considered by PACT as two peripheral isolations and six within‐area events. DIVA was less parsimonious because it required six more post‐speciation dispersal events in addition to the 73 hypothesized by PACT. DIVA reconstructed a widely distributed ancestor, suggesting that most dispersal events occurred earlier, whereas the ancestral area for PACT based on character optimization was the Northern Amazon, suggesting that dispersal events were more recent phenomena.Main conclusions The general area cladogram from PACT indicated that within‐area events, and not vicariance, provide the major mode of speciation for New World emballonurid bats. There was no biological evidence supporting or rejecting sympatric speciation in New World emballonurid bats. However, the geological history, combined with fluctuations in temperature and sea level, suggested within‐area speciation in a changing and heterogeneous environment in the Northern Amazon during the Miocene. This scenario is similar to the taxon‐pulse hypothesis of biotic diversification, which posits repeated episodes of range expansions and contractions from a stable core area such as the Guiana Shield within the Northern Amazon.

Evolutionary Patterns of Morphology and Behavior as Inferred from a Molecular Phylogeny of New World Emballonurid Bats (Tribe Diclidurini)

A molecular phylogeny of New World emballonurid bats based on parsimony and Bayesian analyses of loci from the three different nuclear genetic transmission pathways in mammals (autosomal, X, and Y chromosomes) is well supported and independently corroborated by each individual gene tree. This is in contrast to a single most parsimonious but poorly supported tree based on morphological data, which has only one intergeneric or higher relationship shared with the molecular phylogeny. Combining the morphological and molecular data partitions results in a tree similar to the molecular tree suggesting a high degree of homoplasy and low phylogenetic signal in the morphological data set. Behavioral data are largely incomplete and likewise produce a poorly resolved tree. Nonetheless, patterns of evolution in morphology and behavior can be investigated by using the molecular tree as a phylogenetic framework. Character optimization of the appearance of dorsal fur and preferred roosting sites maps consistently and are correlated on the phylogeny. This suggests an association of camouflage for bats with unusual appearance (two dorsal stripes in Rhynchonycteris and Saccopteryx, or pale fur in Cyttarops and Diclidurus) and roosting in exposed sites (tree trunks or under palm leaves). In contrast, the ancestral states for Old and New World emballonurids are typically uniform brown or black, and they usually roost in sheltered roosts such as caves and tree hollows. Emballonuridae is the only family of bats that has a sac-like structure in the wing propatagium, which is found in four New World genera. Mapping the wing sac character states onto the phylogeny indicates that wing sacs evolved independently within each genus and that there may be a phylogenetic predisposition for this structure. Ear orientation maps relatively consistently on the molecular phylogeny and is correlated to echolocation call parameters and foraging behavior, suggesting a phylogenetic basis for these character systems.

Molecular phylogeny of New World sheath-tailed bats (Emballonuridae: Diclidurini) based on loci from the four genetic transmission systems in mammals

Multiple unlinked loci are surveyed in a methodological approach for mammalian systematics that uses genes from the four pathways of genetic transmission: mitochondrial, autosomal, and X and Y sex chromosomes. Each of these components has different properties, such as effective population size, mutation rate, and recombination, that result in a robust hypothesis of evolutionary history. The utility of this experimental design is tested with bats in the family Emballonuridae and the hypothesis that the New World taxa are monophyletic. Parsimony and Bayesian analyses of the individual data sets give generally congruent topologies with high bootstrap proportions and posterior probabilities for monophyletic clades representing species and genera. The mitochondrial gene has significantly faster rates of substitution, higher levels of homoplasy, and a greater degree of saturation than the nuclear genes that contributed to the loss of phylogenetic signal at deeper branches of the tree. However, there is better resolution and support for the more slowly evolving nuclear introns including a New World clade, indicating a single origin of emballonurid bats in the Neotropics (tribe Diclidurini). One novel subtribe has a hard basal polytomy that is unresolved for all of the nuclear partitions, suggesting a rapid burst of evolution during the diversification of genera. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93, 189–209.

Ultrastructural Organization of the Corpus Luteum of the Indian Emballonurid Bat, Taphozous longimanus (Hardwicke)

The paper describes the ultrastructural organization of the corpus luteum of the emballonurid bat, Taphozous longimanus (Hardwicke). This bat is continuously asychronous breeder, exhibiting aseasonal polyoestry. During the early part of gestation, the luteal cells are compactly arranged with clearly demarcated boundaries, and show only moderate hypertrophy. Ultrastructural study of luteal cells during early pregnancy reveals the presence of irregularly shaped euchromatic nucleus, rod-shaped mitochondria with tubular or vesicular cristae, numerous lipid droplets and profiles of smooth/agranular endoplasmic reticulum in the form of short tubules or vesicles. The close association of mitochondria with lipid droplets and agranular endoplasmic reticulum in the luteal cells suggests that these cells are actively involved in steroidogenesis. During mid-pregnancy, the luteal cells are hypertrophied and are highly vacuolated. Large number of hypertrophied mitochondria, increased profiles of tubular cisternae of smooth endoplasmic reticulum and abundant lipid droplets in the cytoplasm of luteal cells during mid-pregnancy indicate an increase in the steroidogenic activity.