Sexual selection,genital morphology,and copulatory behavior in male Galagos

Variations in penile morphology among galago species are pronounced and complex. Comparative studies of galagos and other primate species show that elongation of the baculum (os penis)is associated with copulatory patterns involving a prolonged period of intromission. The enlarged penile “spines” of male galagos may be important in maintaining a genital “lock” during copulation. In primate species where females mate with a number of partners, sexual selection may have favored the rapid evolution of such features of penile morphology and masculine copulatory behavior. It is suggested that evolution of complex penile morphologies in galagos has been influenced by sexual selection and that such morphological variations are extremely useful in taxonomic studies.     

Penile Morphology and Classification of Bush Babies (Subfamily Galagoninae)

The penile morphologies of nocturnal prosimians are complex and vary considerably between genera and species. Accordingly, comparative morphology can be useful in taxonomic studies, particularly when assessing the status of newly discovered species. I measured features of penile morphology—surface area of the glans penis; shape and size of the keratinized spines on the glans—for populations representing 14 species within the subfamily Galagoninae. Intraspecific variations in penile morphology were relatively minor. By contrast, there are significant differences in several morphological features among closely related, sympatric species, e.g., in the greater bush babies (Otolemur crassicaudatus and O. garnettii) and lesser bush babies (Galago senegalensis and Galago moholi). Assessment of glans area resulted in the recognition of a second needle-clawed form: Euoticus pallidus. Similar divisions exist in the dwarf and greater bush babies with respect to proportional spiny area and characteristics of spine size. I constructed a key based on the presence/absence of certain features—penile spines, dermal markings on the glans, penile lappets—as well as the shape of the baculum and possession of different spinal morphotypes. This key may be used to identify all 14 species of bush babies. Penile morphologies provide a useful guide to specific identity in the Galagoninae, which may be true also for other groups of nocturnal mammals.     

Penile morphology of African mole rats (Bathyergidae): structural modification in relation to mode of ovulation and degree of sociality

The penile morphology and bacular structure of five species of African mole rat are described in relation to the method of ovulation, degree of sociality and polygynandry. We predicted that, with an increase in sociality, and a concomitant decrease in polygynandry and sperm competition, there would be a decrease in penis ornamentation (spinosity) and baculum size. In solitary species of African mole rat with marked seasonal reproduction and induced ovulation ( Bathyergus suillus and Georychus capensis ), males have numerous epidermal spines on the penis. Social, seasonally breeding, induced ovulating mole rats Cryptomys hottentotus natalensis possess less elaborate ornamentation in the form of small protrusions that are rounded at the apex. Two aseasonally breeding eusocial species with spontaneous ovulation Cryptomys damarensis and Heterocephalus glaber have ridges on the penis but lack any elaborate ornamentation. Baculae, however, showed a trend to become proportionally smaller in the solitary species. Our prediction that, with an increase in sociality and a move from induced to spontaneous ovulation, the amount and degree of penile ornamentation declines was, therefore, generally supported.     

Observations on the evolution of the genitalia and copulatory behaviour in male primates

Comparative studies of genital anatomy and sexual behaviour in male primates show that penile morphology and copulatory patterns tend to be more specialized in species which have a multimale or dispersed (non-gregarious) mating system. The penis may be longer and more complex morphologically in such species. Copulatory patterns involving a series of intromissions or prolonged single intromissions are more common than in species with a monogamous or polygynous mating system. Elongation of the baculum occurs in species which prolong intromission into the post-ejaculatory period. Sexual selection may have favoured the evolution of such features in species where females mate with a number of males rather than with a single partner. Relative testis size is also greatest under such conditions and larger testes occur in some non-gregarious or seasonally breeding prosimians, as well as in anthropoids with multimale mating systems.     

A comparison ofGalago moholi in South Africa withGalago zanzibaricus in Kenya

Two populations of small bushbabies that frequently have been regarded as subspecies of Galago senegalensisare compared and contrasted. The animals in South Africa differ from those in coastal forests of Kenya in aspects of their morphology, locomotion, calls, reproduction, diet, social organization, and karyotype. The two forms are clearly separate species, namely G. moholiand G. zanzibaricus.     

Histomorphology of the glans penis in Vespertilionidae and Phyllostomidae species (Chiroptera,Mammalia)

The penises of bats are taxonomically distinctive in size and shape. In addition, they are variable in microscopic anatomy, indicating that histomorphological studies of copulatory organs of bats may help understanding their successful reproductive strategies. We studied adult males of 13 species of vespertilionid and phyllostomid bats. Both families exhibited the basic structure of the vascular penis of mammals: the hydrostatic elements of the corpora cavernosa and the corpus spongiosum surrounding the urethra, as well as accessory cavernous tissue. Variation in the position and amount of the tissues were observed in these families. Vespertilionid bats have a small glans penis with abundant accessory cavernous tissue on the prepuce and a highly variable baculum. The baculum varied in size and morphology, even among congeneric species, such as the three Lasiurus species and the two Myotis species. Phyllostomid species possess no bacula, but vascular structures are present to produce penile stiffening, particularly on the glans. Variation in the microscopic anatomy of the phyllostomid prepuce was observed, for example, Artibeus species had accessory cavernous tissue surrounded by a tunica albuginea, but Carollia perspicillata had two bundles of striated musculature and some adipose tissue; abundant pigments were present in the prepuce of most species.     

The structure and function of the genitalia in the Libellulidae (Odonata)

An outline of the morphology of the secondary genitalia of libellulid dragonflies is given together with a more detailed treatment of the components of the fourth (distal) segment of the penis. The variations of penis structure in 70 species, representing ten of the 11 subfamilies, are surveyed and catalogued. There is remarkable diversity in the presence and form of penis structures, particularly those associated with the medial process, namely the flagelium, cornua and inner lobes. A comparable survey of females shows that they can be provisionally divided into ten types according to the number and size of their sperm-storage organs. Comparisons of penis structures with the sperm-storage organs of females suggests that in species whose females store large amounts of sperm, usually doing so in one or a pair of organs, males possess highly extensible, lobate and bristly penes, commonly equipped with cornua. By contrast, in those species in which the females store small volumes of sperm, usually doing so in three organs, the penes bear either flagella equipped with proximally directed spines or with large terminal barbs, or they have narrow, spiny inner-lobes which resemble flagella. Some functional interpretations are proposed in the light of sperm competition. The variability of genital structure can be interpreted adaptively and does not closely reflect phylogenetic relationships. Functionally convergent structures have evolved a number of times from different origins.     

Spermatophore expulsion in the carrion beetle Silpha perforata (Coleoptera: Silphidae)

Silphinae (Coleoptera: Silphidae) is an abundant decomposer that plays important roles in the ecosystem. However, there is little information about the life history of this taxon. We found sperm displacement behavior in carrion beetle Silpha perforata. Copulating males bit the female's antenna strongly and inserted the penis into the partner's genital organ more than once. We found a white substance on the tip of penis during copulation. We examined whether this white substance is a previous male's spermatophore, which was removed from the mating partner. When females were dissected just after mating, the same substance that often presents on the penis of mating males was found in the bursa copulatrix of females, although the bursa copulatrix of virgin females was empty. Male behavior during copulation with females of different mating history was also observed to confirm that the removal of spermatophores was observed only in copulation with females that have the spermatophores of previous males. Consequently, we estimated that S. perforata males removed spermatophores of previous males from mating partners. In addition, we dissected the males frozen during copulation, and inspected the penis morphology. This observation revealed that the apical part of the penis was usually hidden in the basal part of penis, but expanded and appeared during insertion. This apical part had many spines, which play an important role in sperm displacement and sexual conflict in some species. These results indicate that there is the sperm competition in S. perforata. This is the first report on sperm competition in Silphinae.     

The Large-billed Reed Warbler Acrocephalus orinus revisited

The Large-billed Reed Warbler Acrocephalus orinus is known only from the type specimen, collected in Himachal Pradesh, India, in 1867. The specimen is poorly prepared, and it has been suggested that it could represent an isolated form of the Clamorous Reed Warbler A. stentoreus or an aberrant Blyth's Reed Warbler A. dumetorum . We tested the affinity of A. orinus by (1) re-examining the morphology of the type specimen and (2) amplifying and sequencing a portion of its mitochondrial cytochrome b gene. Both the morphological and the mitochondrial analyses showed the specimen to be similar to dumetorum , but distinct enough to qualify as a species of its own. Relative to dumetorum , it has a more rounded wing, longer bill, longer and more graduated tail with more pointed tail feathers, and larger claws. The divergence in mitochondrial DNA between orinus and dumetorum was 7.8%, well above the value expected between subspecies. A. orinus is smaller than any of the forms of A. stentoreus or the related Australian Reed Warbler A. australis . It has a somewhat longer first primary, more pointed tail feathers and paler, less robust feet and claws. DNA comparison places it in the clade of small unstreaked Acrocephalus warblers, and apart from the clade of large unstreaked warblers that contains stentoreus and australis .     

Galago locomotion in Kibale National Park, Uganda

Very few locomotor studies have been conducted on galagos. This is surprising given their interesting anatomy and ecology, as well as their increasing species diversity. In this study we investigated locomotion and postures in two sympatric galagos species (Galagoides thomasi and Galago matschiei) living in Kibale National Park, Uganda. G. thomasi uses arboreal quadrupedalism and leaping, while G. matschiei is more leaping-oriented. Both species utilize small oblique branches in the mid-canopy. These similarities in substrate use are most likely due to the similar body sizes and anatomies of the two species, as well as to the structure and availability of trees in Kibale National Park. Lastly, we compare the locomotor patterns of G. thomasi and G. matschiei with those observed in the few other quantitative locomotor studies available for galagos.     

长爪沙鼠阴茎头的组织学研究及五种鼠阴茎头的扫描电镜观察

本文对８例长爪沙鼠（Ｍｅｒｉｏｎｅｓｕｎｇｕｉｃｕｌａｔｕｓ）幼年、亚成年、成年和老年雄性个体的阴茎头组织进行连续切片。结果表明,阴茎头的外环层和阴茎骨近支由阴茎海绵体衍生而来;内环层、尿道小瓣、阴茎骨远支和侧支由尿道海绵体衍生而成。采用扫描电镜观察了长爪沙鼠、子午沙鼠（Ｍ．ｍｅｒｉｄｉａｎｕｓ）、大沙鼠（Ｒｈｏｍｂｏｍｙｓｏｐｉｍｕｓ）和甘肃绒鼠（Ｅｏｔｈｅｎｏｍｙｓｅｖａ）、黑腹绒鼠（Ｅ．ｍｅｌａｎｏｇａｓｔｅｒ）共５种１６例的阴茎头表皮棘,发现其形态、数量和分布有属、种间差异性和相对稳定性,沙鼠属（Ｍｅｒｉｏｎｅｓ）３种的表皮棘均呈牛角状的圆锥体,斜向排列成行;而绒鼠属（Ｅｏｔｈｅｎｏｍｙｓ）内甘肃绒鼠为球状表皮棘,黑腹绒鼠为牛角状,排列均不规则。因此,阴茎头表皮棘与阴茎骨、阴茎头软体结构均有分类学意义。     

Tertiary sex ratios in wild Galago population (Mammalia: Primates)

Previous studies have proposed that species within the genus Galago exhibit a secondary sex ratio that is strongly skewed (approximately 70%) in favour of males. It has further been suggested that this sex ratio is maintained into adulthood. We present data obtained from 669 adult galagos, representing eight wild populations and five species, to indicate that the sex ratio among sexually mature individuals is close to parity. If the observations regarding sex ratios at birth are correct, this implies that juvenile/sub-adult males suffer significantly higher mortalities than do their female counterparts.     

Gametophytic simplicity in Laurasian and Gondwanan Polytrichopsida — the phylogeny and taxonomy of the Oligotrichum morphology

Abstract

Phylogenetic analyses have largely resolved generic and higher level relationships within the Polytrichopsida, enabling polarisation of characters and the identification of macro-evolutionary trends. Topologies show strong geographic patterning, with major groups having predominantly Northern or Southern Hemisphere distributions and some general morphologies having arisen independently on either side of the equator. While most cases of apparent convergence have been taxonomically visible due to sufficient higher-level characters being present to distinguish unrelated genera, convergent reduction may have resulted in conflation of similar gametophytic morphologies in classification. We present further evidence for the polyphyly of Oligotrichum DC. as currently circumscribed, showing how this morphology has probably arisen through reduction on multiple occasions to produce distinct lineages that have lacked taxonomic identity. We present a preliminary arrangement of the species currently recognised in Oligotrichum, accommodating selected Southern Hemisphere taxa in Itatiella G.L.Sm., and combining Atrichopsis compressa (Hook.f. & Wilson) G.L.Sm. and Oligotrichum tenuirostre (Hook.) A.Jaeger under Notoligotrichum G.L.Sm. For several species that clearly do not belong in Oligotrichum but remain of ambiguous affinity to other genera we avoid making new combinations, as ongoing combined molecular and morphological studies have considerable potential to elucidate their relationships in the near future.     

Morphological variability in a red seaweed: confirmation of co-occurring f. lessonii and f. chauvinii in Chondracanthus chamissoi (Rhodophyta,Gigartinales)

Variability in thallus morphology is common in red seaweeds. Two co-occurring forms have been described for Chondracanthus chamissoi based mainly on blade width. To determine whether two distinct forms or a range of intermediate morphologies occur in C. chamissoi, thalli were collected from three localities in southern Chile in autumn–winter, repeating the sampling in one locality in spring and in summer. In each occasion, individual sporophytic and male and female gametophytic clumps were collected, and the longest blade with intact apex from each clump was evaluated. Blade length, width, density of spines, axis curvature and thickness, and pinnule length and width were evaluated in each blade. Principal components analyses separated two groups of thalli, one group with narrow, thick, and curved (concavo-convex) blades, with few spines consistent with f. lessonii, and another with broad, thin, and flat blades, with many spines consistent with f. chauvinii. These variables also had bimodal frequency distributions. Pinnule measurements were mainly associated with differences among sporophytes and gametophytes. Age (length), phase of the life cycle, and sex were not related to the forms. Furthermore, thalli of both forms were collected side by side in the study sites and throughout the year so the occurrence of the two forms was not attributable to local environmental conditions. In this species, secondary basal disks are produced after attachment of apexes to the substratum. These disks may produce blades with a modified morphology in a way similar to proliferations and regenerations described for Schottera nicaeensis.     

New species of the Monocotylidae (Monogenea) from the stingray Dasyatis tortonesi Capapé (Euselachii,Dasyatidae) off the Tunisian coast,with comments on host-specificity and the specific identities of Mediterranean stingrays

Heterocotyle capapei n. sp. and Thaumatocotyle tunisiensis n. sp. are described from the gills and the nasal cavity, respectively, of Dasyatis tortonesicollected from the Tunisian coast. H. capapei is distinguished from other species in the genus by the morphology of the penis, which is conical and has a long narrow distal point. T. tunisiensis differs from all known species of Thaumatocotyle by the shape and size of the penis. The host Dasyatis tortonesi has long been confused with D. pastinaca. Our study shows that their monogeneans are oioxenic, suggesting that D. pastinaca and D. tortonesi are distinct species. These results suggest that the monogenean parasite fauna could be used as a diagnostic tool for species identification: these parasites may, therefore, represent good biological indicators. The host-specificity of the Heterocotylinae and Merizocotylinae is discussed.