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1.
Tylototriton shanjing Nussbaum, Brodie & Yang, 1995 was described as a distinct species hidden before under the widely distributed T. verrucosus Anderson, 1871. Therefore, papers published before 1995, including those on reproductive biology, could not distinguish between these two close relatives. Consequently, data on the reproductive biology of T. shanjing are scarce. Here, we report on the first captive breeding of T. shanjing in the Aquarium of the Cologne Zoo, and we document the ontogenetic developmental stages and describe the larva for the first time. Moreover, we give a literature review for both T. verrucosus and T. shanjing and compare our data with published information referring undoubtedly to the latter species. To avoid future misidentifications and to facilitate the composition of breeding groups, we present an identification key for the East Asian salamandrid genera in general, and for the species of Tylototriton in particular.  相似文献   

2.
The reproductive biology and feeding habits of the electric fish Brachyhypopomus gauderio were studied. The species has seasonal reproductive behavior, with breeding occurring during the Southern Hemisphere spring and summer, and having a positive relation with the photoperiod variation. Brachyhypopomus gauderio was defined as a fractional spawner, with low relative fecundity and high first maturation size. Sexual dimorphism was registered, males undergoing hypertrophy of the distal portion of caudal filament. The results on reproductive biology herein obtained are in agreement with data concerning gymnotiforms from Southern Brazil and Uruguay, pointing to an ecological pattern for the species from high latitudes, differing from species with tropical distribution. According to the analysis of the food items, B. gauderio feed mainly on autochthonous insects, likewise the other gymnotiforms previously investigated, leading to conclude that there is no variation on the diet of the species of the order related to climatic conditions or even to habitat of occurrence.  相似文献   

3.
Caesalpinia echinata (brazilwood) is a threatened tree endemic to the Brazilian Atlantic forest with a global importance as it is worldwide used to manufacture the most desirable bows for violins, violas, and cellos. Although there is an international initiative for its conservation, there is a lack of studies on the reproductive biology of the species, as for the genus, a fundamental understanding for the conservation of any species. In this paper, we investigated the phenology, pollination, and breeding system of C. echinata, presenting some conservation guidelines for the species, together with a review of studies on the reproductive biology in Caesalpinia s.l. The genus has a complex taxonomic history with recent attempts to reassign its limits. Pending a final resolution of the placing of some species (including C. echinata) our revision covers the traditional Caesalpinia s.l. and includes annotations indicating to which segregate genus each species is now considered to belong, as well as the appropriate combination where this has already been published. Field work was undertaken from October/2004 to December/2006 at the Tapacurá Ecological Station, northeastern Brazil. Flowering occurred mainly in the dry season and the peak of seed dispersal was at the beginning of the wet season. Anthesis is diurnal, lasting 1 day. The flowers are zygomorphic, yellow, sweet-scented, and the effective pollinators were mainly medium-sized to large bees of the genera Centris and Xylocopa, together with the introduced Apis mellifera. Nectar volume and sugar concentration averaged 2.9±1.0 μL and 29.5±9.4%, respectively. The ovary has 1–4 ovules (2.35±0.58) and the pollen/ovule ratio was 5631.2; pollen viability was high (95.9±4.8%). Natural fruit set was low (9.2%) with mature fruits averaging 1.7±0.9 seeds. Results of the controlled pollinations and analysis of pollen tube growth revealed C. echinata presents late-acting self-incompatibility. The pollination biology and breeding system of C. echinata are discussed, together with available data on its genetics and physiology, in terms of best conservation practice for this endangered species. Data on the reproductive biology of the genus are scarce, revealing the predominance of bee pollination and SI system, with the occurrence of late-acting self-incompatibility mechanisms in some species.  相似文献   

4.
5.
Birgus latro (L.) is the largest terrestrial hermit crab in the world. The species is widely distributed on remote Indo-Pacific islands of the tropics, but it is rapidly declining and is currently classified as data deficient on the IUCN red list. This review provides a synopsis of both published and unpublished data on the biology and ecology of B. latro. It highlights the lack of robust biological information on the species’ basic biology, particularly in the juvenile and reproductive phases, while behavioural ecology studies are few and report conflicting data between populations. Population studies indicate that B. latro may have limited recruitment events throughout its range, emphasising the need for more systematic research to clearly identify factors that influence successful recruitment events. The review highlights the paucity of substantiated peer reviewed studies on this species and emphasises the need for further systematic research.  相似文献   

6.
The 18 penguin species are exclusively and widely distributed in the Southern hemisphere, from the Equator to the Antarctic continent, and are thus submitted to various ecological constraints in their reproductive strategy. This results in a high variability in all aspects of the breeding biology of the different species. Although penguins appear primarily adapted for a marine existence, they remain dependent on land for breeding, rearing young, and moulting. Here we describe and compare the breeding cycle of all the penguin species, highlighting the characteristics of each species in terms of breeding range, population status, threats induced by environmental changes, duration of the different phases of the breeding cycle, mate fidelity, body mass, body height, egg mass and duration of egg formation. We also focus on the breeding cycle of the genus Aptenodytes, since it largely differs from the breeding cycle of most of the other penguin species.  相似文献   

7.
The sexual system in corals refers to the spatial and temporal pattern of sexual function within an individual coral polyp, colony or population. Although information on sexual systems now exists for over 400 scleractinian species, data are still lacking for some important reef-building taxa. The vast majority of scleractinians are either simultaneous hermaphrodites or gonochoric with other sexual systems rarely occurring. Diploastrea heliopora is one of the most ubiquitous and easily recognised reef-building species in the Indo-West Pacific; however, surprisingly little is known about its reproductive biology. The aim of the present study was to examine the reproductive biology of D. heliopora colonies on chronically impacted, equatorial reefs south of Singapore. Here we show that in Singapore, D. heliopora is a broadcast spawner with predominantly gonochoric polyps. Colonies, however, contained male, female and a low proportion of cosexual polyps during the 14-month sampling period. The most plausible explanation for this is that polyps switch sexes with oogenic and spermatogenic cycles occasionally overlapping. This leads to colony level alternation of sex function within and between breeding seasons. While this sexual system is atypical for scleractinians, it supports molecular evidence that D. heliopora is phylogenetically distinct from species formerly in the family Faviidae.  相似文献   

8.
Polyploidy is the most common chromosomal mechanism involved in the evolution of plants. However, the emergence of polyploid individuals does not guarantee the establishment of a new lineage, and the relationship between polyploidy and reproductive biology is therefore relevant. Libidibia ferrea is a legume tree that has diploid and tetraploid populations. In this work we analyse the reproductive biology of the species to verify the degree of reproductive isolation between the two cytotypes. Observations on phenology, floral morphology, biology, and visitors, breeding system, reproductive success and reproductive isolation were made for both cytotypes in two municipalities of northeastern Brazil. Cytotypes differed for all morphometric parameters analysed, with tetraploids exhibiting higher mean values than diploids. Both cytotypes had the same effective pollinators (native bees from the genera Centris and Xylocopa, and the introduced Apis mellifera). However, since stamens of diploids and tetraploids were of different size, it is possible that spatial separation occurs when pollen of each cytotype is deposited on a bee’s body. Diploids were self-incompatible (ISI?=?0) and exhibited high fruit-set after intraploidy crossing (20?%), whereas tetraploids were self-compatible (ISI?=?0.47) and set only 3.9?% of fruits after intraploidy crossing. Both cytotypes showed low fruit- and seed-set under natural conditions, and there was no fruit-set after crosses between them. Data are discussed in relation to the establishment of polyploids, to the pattern of distribution of the species and to the taxonomic implications. The cytotypes of L. ferrea should be considered as distinct species, since they are reproductively isolated from each other.  相似文献   

9.
The reproductive biology of six native Tillandsia species that co-occurred in woody areas of Santa Fe Province (Argentina) was studied for floral biology, breeding systems and reproductive success. Flower longevity, floral phases, hand self- and cross-pollinations or natural pollinations and fluorescence microscopy observations of post-pollination events were analysed. Also pollen/ovule (P/O) ratio and pre-emergent reproductive success (PERS) were compared between species. In T. aëranthos, T. ixioides and T. meridionalis, self-pollinated flowers mostly failed to form fruits, and fluorescence microscopy studies showed that in selfed pistils pollen tube growth was arrested in the style. It is likely that these species have homomorphic, gametophytic self-incompatibility. In contrast, T. capillaris, T. tricholepis and T. recurvata regularly formed fruits following autonomous self-pollination. Floral traits, the P/O ratios and PERS indices correlate with the breeding systems found in these two groups of species: the three selfing species have inconspicuous closed flowers, and they have low P/O ratios and high PERS values. In contrast, the three self-incompatible (SI) species have conspicuous flowers with relatively high P/O and low PERS values. We described here three new cases of SI in Tillandsia species subgenera Anoplophytum and confirm the autogamous and cleistogamous status in three species of Tillandsia subgenera Diaphoranthema.  相似文献   

10.
Low-temperature environments interfere with plant reproduction by reducing the frequency of pollinators, and this may favour reproductive strategies such as self-pollination and apomixis. Tibouchina pulchra is a common tree species that occurs at high and low sites of the Brazilian Atlantic rainforest. This study focussed on the pollination biology and breeding system of this species, describing the pollinators and the reproductive success at the two sites of an elevational gradient. Observations were made to determine extent of flowering and fruiting, to identify the richness and abundance of pollinators, and to record data on the floral and reproductive biology at these two sites. Despite more dense flowering at the high site, five visits of bees (two species) were recorded during the observation time (60?h), whereas at the low site there were 948 visits (seven species) during the same period. In contrast with the low site, the flowers of the high site released and received few pollen grains on the stigma. At the high site less fruit was set with fewer seeds as a result of open pollination than at the low site; at that site, however, more seeds were obtained from cross-pollination than at the low site. Tibouchina pulchra is self-compatible; however it is not apomictic and needs pollinators for seed set at both sites. Life-history traits other than the breeding system, for example more dense flowering, advantage of greater fertility in cross-pollination, and multiple reproductive events during the lifetime of the tree may reduce inbreeding depression, increase the hybrid vigour, and balance the lack of pollinators at the high site.  相似文献   

11.
Many Asteraceae species inhabit open vegetation areas and, as a rule, members of this family have dry, wind-dispersed fruits. Tilesia baccata, on the other hand, occurs in forested areas and, differently from all neotropical Asteraceae, has fleshy fruits with ornithochorous characteristics. However, no studies have confirmed the dispersion by birds or any other aspect of the reproductive biology of this unique Asteraceae. The present study aims to investigate the reproductive phenology, floral biology and breeding system and to identify the pollinators and seed dispersers of T. baccata. The study was carried out in a natural population located in a semideciduous forest (Viçosa, Minas Gerais State), southeastern Brazil. The reproductive cycle of T. baccata is annual and seasonal, related to precipitation, temperature and day length. The longevity of flowers and capitula depends on the performance of pollinators and dispersers. Hand pollination tests showed that the species is self-incompatible and therefore dependent on synchronous flowering and pollinator availability. Pollination occurred in the morning, in the period of pollen availability, and social bees were the major pollinator group. Seeds are dispersed by frugivorous birds, that swallow the ripe fruits and defecate viable seeds later. Our study confirmed the bird dispersal of Tilesia baccata seeds and also demonstrates that pollinator activity and fruit removal by birds influence the magnitude of activity and the intensity of flowering and fruiting.  相似文献   

12.
The reproductive biology and feeding habits of the hypopomid Brachyhypopomus bombilla were studied. The species has seasonal behavior, with breeding and feeding activity occurring mostly during the Southern Hemisphere spring and summer. We defined fractional spawning for the species and a relative fecundity similar to those previously reported for other gymnotiform species. According to the analysis of the food items, B. bombilla was included in the trophic category invertivorous, feeding mainly on autochthonous insects. The reproductive periods of males and females as well as female feeding activity were significantly related to the photoperiod. During a period of 5?months, when the lowest water temperatures and shortest photoperiod were recorded, all the specimens of B. bombilla were found buried in the muddy bottom of the creek, with lower electric organ discharge activity, empty stomachs, and gonads in early stages of the maturation process. This period, herein defined as a dormancy period, is reported here for the first time for a species of the Gymnotiformes order.  相似文献   

13.
The reproductive biology of the European badger (Meles meles) is of wide interest because it is one of the few mammal species that show delayed implantation and one of only five which are suggested to show superfetation as a reproductive strategy. This study aimed to describe the reproductive biology of female Irish badgers with a view to increasing our understanding of the process of delayed implantation and superfetation. We carried out a detailed histological examination of the reproductive tract of 264 female badgers taken from sites across 20 of the 26 counties in the Republic of Ireland. The key results show evidence of multiple blastocysts at different stages of development present simultaneously in the same female, supporting the view that superfetation is relatively common in this population of badgers. In addition we present strong evidence that the breeding rate in Irish badgers is limited by failure to conceive, rather than failure at any other stages of the breeding cycle. We show few effects of age on breeding success, suggesting no breeding suppression by adult females in this population. The study sheds new light on this unusual breeding strategy of delayed implantation and superfetation, and highlights a number of significant differences between the reproductive biology of female Irish badgers and those of Great Britain and Swedish populations.  相似文献   

14.
Fonio millets (Digitaria exilis, D. iburua) are minor but important indigenous cereals in the semiarid areas of West-Africa. Recent interest in breeding strategies for these crops requires a better understanding of their biology and genetics. Amplified Fragment Length Polymorphism (AFLP) markers were employed to assess the phylogenetic relationships among cultivated fonio species and some polyploid wild relatives and examine proposed hypotheses on fonio ancestry. The AFLP analysis was found quite suitable for identifying each species. A very strong genetic affinity (over 92% similarity) was detected between the wild D. longiflora and D. ternata and the cultivated D. exilis and D. iburua, respectively. These data provided additional molecular evidence supporting the previous view of direct domestication of fonio millets from these two wild species. High genetic divergences were expectedly found between fonio species and the other taxonomically distant Digitaria taxa investigated. The results also revealed D. ciliaris and D. sanguinalis as separate species sharing close ancestry. Selfing experiments and subsequent progeny analyses using three isozymes supplemented by AFLPs were further conducted to determine the reproductive system in fonio millets. The results revealed apomixis as absolute mode of reproduction of these crops, except D. exilis in which 2% residual sexuality was detected. Additional data documented on seed set and pollen viability suggested that apomixis in fonio would be of pseudogamous type. The data also revealed fonio crops as highly self-compatible and of allopolyploid origin. This study adds new information about the reproductive system and the evolution of fonio, contributing to the knowledge on their biology, and thus providing useful subsides for future genetic improvement of these valuable crops.  相似文献   

15.
Genetic identification methods have become increasingly important for species that are difficult to identify in the field. A case in point is Pelophylax water frogs. While their morphological determination is highly complex, they include species protected under EU law and some that are classified as invasive. Additionally, genetic data can provide insights into their complex breeding systems, which may or may not involve the reproductive dependency of one species on another. Here, we generate baseline data for water frog monitoring in Luxembourg. We applied a countrywide sampling approach and used SNPs generated by ddRAD sequencing to identify individuals and infer the breeding systems present in the country. We found Pelophylax lessonae and P. kl. esculentus throughout Luxembourg, mostly living in syntopy. In general, a reproductive dependency of P. kl. esculentus on P. lessonae (L‐E system) was revealed. Besides this general system, we detected triploid P. kl. esculentus in six ponds. This indicates a modified L‐E system with reproductive dependency of the triploids on the diploid P. kl. esculentus. The invasive P. cf. bedriagae was detected in three ponds in southern Luxembourg, with evidence for hybridization with native water frogs. In addition to the ddRAD data, we tested a simple genetic method for future monitoring based on the MND1 marker. It showed in almost all cases, an identical species identification as the ddRAD data and was successfully applied to DNA extracts from mouth swabs. Combining this method with our baseline data will enable informed choices for the protection of native water frog species in Luxembourg.  相似文献   

16.
It has profound implications for species invasions and fitness, how weeds achieve reproductive success. We present the first study on the reproductive biology of Stellera chamaejasme, a toxic perennial weed which is abundant in the alpine meadows on the eastern Tibetan Plateau of China since the 1960s. S. chamaejasme has synchronogamy and herkogamous flowers, which last for about 11 days. Flowers can be yellow, white or reddish. Our results suggest that this species is self-incompatible and depends entirely on pollen vectors for seed production. All the pollinators observed were Lepidopteran species; however, the pollinator assemblage was significantly different among populations and likely independent on floral colour. Reproductive success and invasion of the weed might be a complex function of floral traits, breeding system and pollination ecology. Generally, plants with generalized pollination system are more invasive. However, our results suggest that specialized flowers and self-incompatibility in the present case may not prevent invasion of the weed.  相似文献   

17.
In the last two decades the subtropical red tomato spider mite, Tetranychus evansi, has expanded its geographical distribution and emerged as a major invasive agricultural pest. The mite is considered to be native to South America. Since its first report from north-eastern Brazil in 1952, it has been reported from different continents. This paper reviews literature on several aspects of the biology of T. evansi related to its status as an invasive species. It addresses taxonomical issues, occurrences, life history traits, host-plant interactions, genetic diversity of geographical isolates and worldwide colonisation pathways. It also presents updated data which allowed the assessment of the actual worldwide distribution of this species, from its discovery to the latest reports. As T. evansi is considered an emerging agricultural pest, we also present data based on modelling of the potential of T. evansi to colonize new geographical areas. In addition, this review presents past and current research on natural enemies of T. evansi potentially useful for its biological control. While summarizing the knowledge on T. evansi, the review emphasizes research possibilities that are worth pursuing, mainly concerning the ability of T. evansi to establish new populations and to detect new promising natural enemies.  相似文献   

18.
Most of the reproductive modes of frogs include an exotrophic tadpole, but a number of taxa have some form of endotrophic development that lacks a feeding tadpole stage. The dicroglossid frog genus Limnonectes ranges from China south into Indonesia. The breeding biologies of the approximately 60 described species display an unusual diversity that range from exotrophic tadpoles to endotrophic development in terrestrial nests. There have been mentions of oviductal production of typical, exotrophic tadpoles in an undescribed species of Limnonectes from Sulawesi, Indonesia. Here we examine newly collected specimens of this species, now described as L. larvaepartus and present the first substantial report on this unique breeding mode. Typical exotrophic tadpoles that are retained to an advanced developmental stage in the oviducts of a female frog are birthed into slow-flowing streams or small, non-flowing pools adjacent to the streams.  相似文献   

19.
Geographic variations in reproductive traits are important for evolutionary biology, but often difficult to investigate because of the need for a large-scale survey and the ephemeral nature of secondary sexual characteristics. Here, using web image searches (Google Images and Twitter), we revealed large-scale geographic variations (>1500 km) in breeding timing and nuptial coloration in the mutually ornamented fish, Japanese dace (Tribolodon hakonensis). As this fish is easily caught and many anglers upload their photographs on the web, we were able to find a total of 401 high-resolution photographs from all over Japan. Breeding periods were determined from dates of photographs with/without nuptial coloration, which matched with previous studies. We also found that breeding periods might have advanced three weeks over the last 80 years in the Chitose River, potentially because of climate change. Additionally, the pattern of latitudinal cline for breeding timing revealed delayed timing in higher latitudes, although regional variations were also high. Finally, we quantified the patterns of nuptial coloration for this mutually ornamented fish, and confirmed that over 80% of individuals showed typical colorations, but others showed rare phenotypes that were never previously described, including an intermediate coloration between T. hakonensis and a potentially hybridizing species, T. brandtii. Our web-based method for estimating breeding phenology could be adopted for organisms with temporal sexual characteristics, such as plants (e.g., flowering time) and some fishes. Web image analyses are still preliminarily with many limitations, but could be promising for investigating variations in visible traits.  相似文献   

20.
Results from data collected during the 1978–1979 breeding season on the reproduction of Lemur variegatus at the San Diego Zoo provide information which generally supports previously published reports on this species. Comparison of selected results from these data to a larger data base of which they are a part makes it possible to resolve some of the discrepancies between reports. Certain aspects of the reproductive biology of this species may then be generally characterized with confidence: The onset of seasonal breeding as evidenced by estrous behavior begins as early as mid-December in the northern hemisphere and may continue through March; genital changes associated with estrus in females last 9.85 ± 1.67 days (± SD); female receptivity occurs 7.0 ± 1.53 days after the onset of these genital changes and lasts 12-24 hours, during which breeding occurs; gestation averages 99.47 ± 4.19 days; the peak birth season is April–May; litters normally contain two to three offspring, with full-term neonates weighing an average of 104.63 ± 19.10 grams. In addition, L variegatus appears to be highly resistant to the impact of captivity on both its reproductive physiology and behavior, as indicated by the 100% breeding success of the diversely reared and managed groups of study animals.  相似文献   

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