共查询到8条相似文献,搜索用时 15 毫秒
1.
《Journal of Natural History》2012,46(21-22):1273-1289
This study tests the hypothesis that sympatric species of Hyalella may show different reproductive strategies that permit their coexistence. Ovigerous females were collected monthly with nets during a 1-year period in two aquaculture trout ponds in Vale das Trutas, São José dos Ausentes County, southern Brazil. In both species there was a decrease in the number of embryos in the brood pouch during embryonic development, and an increase in egg volume. However, the two species differed in the body size of ovigerous females, number of eggs and juveniles per female, brood mortality rate, egg size and hatching size of juveniles. Egg production continued throughout the year, with the highest number of eggs produced during winter and spring by Hyalella pleoacuta, and winter, spring and autumn by Hyalella castroi. These differences in the reproductive traits of species of Hyalella may permit their coexistence in nature. 相似文献
2.
Reproduction is a critical event in the life cycle of animals, and a high amount of energy is allocated to it. The aim of this study was to characterize the reproductive biology of two recently described species of Hyalella from the north-east region of state of Rio Grande do Sul in southern Brazil. The specimens were collected during 12 months from a stream source (Hyalella georginae) and from a water reservoir (H. gauchensis), in Palmeira das Missões municipality, state of Rio Grande do Sul. Upon sampling, ovigerous females and pairs in precopulatory behaviour were separated into microtubes. In the laboratory, the cephalothorax length (CL in mm) of all specimens was measured. Male size at onset of sexual maturity was larger than that of the females, in both species. There was a correlation between the size of paired males and females: larger males carried larger females, in both Hyalella species. Precopulatory pairs were found throughout the year; however, H. georginae had a higher frequency in spring, and H. gauchensis in autumn. There was a positive correlation between the CL of ovigerous females and the number of eggs/juveniles. A reduction in the number of eggs throughout the embryonic development was observed in H. georginae. The average fecundity of H. georginae was significantly higher than H. gauchensis. The differences between the reproductive biology of these species may be related to the physical and environmental conditions at which they are exposed in their habitats. 相似文献
3.
《Journal of Natural History》2012,46(2):351-359
The importance of calceoli (male antennular organs) in mate recognition of Gammarus pseudolimnaeus Bousfield was examined in the laboratory. The relationship between female receptivity and their moult stage was examined by comparing the moult stage of amplexed and non-amplexed females. The former were clearly in later moult stages and thus closer to ovulation. Ablation of the antennular 2 flagella, which uniquely possess the calceoli, had no effect on the ability of males to find, evaluate and amplex with receptive females. Morphological examination verified the complex nature and apparent lack of innervation of calceoli. We propose that the calceolus functions as a general environmental vibrioreceptor, necessary in the male because of its greater level of activity. 相似文献
4.
《Journal of Natural History》2012,46(17):2077-2094
The species of Hyalella living in the southern extreme of South America have several common morphological features. The uniqueness of this morphology presents a good argument for inferring phylogenetic relationships among them. The species are concentrated, although not exclusively, in the Patagonia of Chile and Argentina. The group is called here ' patagonica complex'. These species are not the only Hyalella present in the area, however. Hyalella simplex Schellenberg, 1943, with no morphological affinities to the patagonica complex is also present, and is one of the few other species outside the complex living in the continental extreme south of South America. Hyalella simplex is redescribed in this paper. Two species of the patagonica complex have been recorded for the area: H. neonoma Stock and Platvoet, 1991 and H. araucana Grosso and Peralta, 1999. H. fossamancinii Cavalieri, 1959, another species in the complex, is found high in the Andes. The new species H. franciscae described in this work is added to the complex. 相似文献
5.
《Journal of Natural History》2012,46(17):1327-1347
Two new species of the genus Alexandrella are described: A. mandibulata and A. martae. One species, A. mixta, is considered a junior synonym of the type species A. dentata. The genus now comprises six species, all of which are restricted to either the Antarctic or sub‐Antarctic region or the South Pacific. Oostegites are observed to be present on pereopod 1 in two Alexandrella species. This is a novel morphological trait among the Amphipoda. Developmental information is presented for two other Alexandrella species, in which the mandibular incisor is seen to be modified from strongly toothed in marsupial young to totally smooth in mature specimens. Also the armature dorsally on their body and the morphology of the telson undergo conspicuous allometric changes. A key to all known Alexandrella species is provided. 相似文献
6.
7.
《Journal of Natural History》2012,46(12):1767-1780
Three species of Nematomorpha were found in a survey of the ground beetles of Scottish agricultural land, Gordionus violaceus (Baird) and two undescribed new species, G. linourgos sp. nov. and G. diligens sp. nov. The morphology of all three species is studied with the aid of SEM, and the characteristics of the cuticle and the male terminal lobes described in detail. All species were found to be parasitic in ground beetles of the family Carabidae, in nine different species (Nebria brevicollis (Fabricius), Harpalus latus (Linnaeus), four species of Pterostichus, and three species of Calathus). Gordionus violaceus is also reported to be a parasite of the spider Arctosa alpigena (Lycosidae). Up to four specimens were found in the same host, typically one adult and several juvenile forms. Parasitized hosts had severe alterations of their reproductive, digestive and secretory systems. The three species of Gordionus were mostly found in grasslands and coniferous forest, most abundantly in June and July. 相似文献
8.
Charles S. Henry Stephen J. Brooks James B. Johnson Atsushi Mochizuki Alinaghi Mirmoayedi Peter Duelli 《Journal of Natural History》2018,52(25-26):1603-1635
Chrysoperla shahrudensis sp. nov. is discovered in northern Iran, co-occurring with at least five other cryptic species of the Chrysoperla carnea-group. It is distinguished by the volley period and tonality of its courtship duetting song. Another Asian species from alpine meadows of northern Kyrgyzstan, previously C. ‘adamsi-K’ but here named Chrysoperla bolti sp. nov., has a song distinct from but convergent with both C. shahrudensis and North American Chrysoperla adamsi. Coordinated duets can be established in the laboratory between individuals of C. shahrudensis and recorded songs of either C. bolti or C. adamsi. Such functional song equivalence in distinct allopatric species suggests that repeated episodes of parallel speciation can drive the origin of cryptic species diversity in lacewings. Morphology, life history, and ecology of larvae and adults of C. shahrudensis and C. bolti are then formally described. Adding C. shahrudensis to a large mitochondrial DNA data set for ≈ 21 species shows it to be similar to neither C. adamsi nor C. bolti, further supporting independent, convergent evolution of song rather than song similarity due to relationship. Although C. bolti and C. shahrudensis are both from Asia and share some basic temporal song features, the two taxa are distinct, allopatric biological species.
www.zoobank.org/urn:lsid:zoobank.org:pub:D9B7BDC9-6C09-468B-A6B-D378628EC557 相似文献