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1.
Observations were made in Fiji on the adaptive strategies of a marine gerrid, Halobates fijiensis , a species of the only genus of insects to have successfully colonized the open sea. The immature stages spend most of their time in flotillas on sheltered water close to mangroves, whereas adults usually occur singly and on both sheltered and open water behind the protecting reef systems. Wind has a decisive influence on the distribution of H. fijiensis: in strong onshore winds, all stages, including adults, remain close to the shelter of mangroves, but in calm conditions, older immatures venture considerable distances from the mangroves. Halobates fijiensis feed on floating, dead insects. Adults of the chironomid fly Tanytarsus halophilae , whose larvae live on intertidal sea-grasses, accounted for over 60% of the prey items recorded. Halobates fijiensis feeds at around the time of high water, either as individuals or in small, well-dispersed groups. Eggs are laid on intertidal turtle grass (Syringodium) , green coralline algae (Halimeda) or occasionally coral rubble, at or shortly after the point of low water on days of extreme low spring tides. Halobates fijiensis is preyed upon by the robber-fly Clinopogon scalaris (Diptera: Asilidae). Field observations showed that there is a clear effect of group size on the distance at which an approaching predator model is detected.  相似文献   

2.
Five species of sea skaters, genus Halobates Eschscholtz, are the only insects to have successfully colonized the open ocean. In addition, 38 species are found in sheltered coastal waters throughout tropical Indo-Pacific. The taxonomy of the genus is relatively well known, and the phylogeneuc relationships between extant species have recently been analysed (using cladistic methods). In the present paper, we describe the first fossil species of sea skaters, Halobates ruffoi sp. no v. from the Eocene deposit 'Pesciara di Bolca', in the province of Verona, northeastern Italy (geological age about 45 Myr). The significance of this fossil in setting the time scale for the reconstructed phylogeny and anagenesis of adaptive features of sea skaters, and in understanding the evolution and historical zoogeography of these marine insects is discussed.  相似文献   

3.
Abstract The tolerance to temperature increase was tested for Halobates individuals collected during two cruises in the western tropical Pacific Ocean (MR‐06‐05‐Leg 3, December 21, 2006–January 12, 2007, 0°N‐8°N; KH‐06‐02‐Leg 5, August 18–31, 2006, 12°N–17°N). High temperature coma experiments were conducted on adults and 5th instar larvae. On average, H. sericeus (distributed in the wide latitude zone of 5°N–40°N), H. germanus (distributed in the moderate latitude zone of 0°N–35°N) and H. micans (distributed mainly in the lower latitudes around the equator) were on average paralyzed at 35.6°C (SD: 0.89), 32.9°C (SD: 2.17) and 31.6°C (SD: 2.60), respectively (P= 0.035). According to the current dynamics during the cruise, the colony of H. sericeus at one station (5°N 137°E) may have been transferred from the northern area of 14°N by three currents (North Equatorial Current, Mindanao Current and North Equatorial Counter Current) to the area of 5°N 138°E. Extremely high heat resistance was shown by the adults of H. germanus in the sea area around the equator. Dynamic current and air movements in this area around the equator, that is a “warm seawater pool”, could be hypothesized to be related to the high resistance to heat shown in this study.  相似文献   

4.
Sea skaters, genus Halobates Eschscholtz, 1822, are the only marine insects living in mangrove beds and the tide pools of coral reefs, both of which provide dramatically variable habitats daily by virtue of tide-driven changes in surface level. Females of H. japonicus Esaki, 1924 were collected from three distinct aggregations in a single bay (24°27′5″N, 124°8′40″E) on 1–5 November 2006. Two aggregations were formed in respective tide pools of the coral reef and one was formed in the mangrove beds. Amplified fragment length polymorphism markers were used to detect the persistency of each aggregation at a mesoscale. The results suggested that H. japonicus repeatedly immigrated from outside the bay to establish a meta-population of several deme groups. Aggregations along the coastline had some persistency to the line itself and had little tendency to cross to the opposite shore, even when the distance was short.  相似文献   

5.
This study was performed to clarify how weather and current dynamics affect the resistance to temperature change in the oceanic sea skaters, Halobates. Heat coma temperature (HCT) was measured for the adults and 5th instar larvae of four Halobates species collected from a fixed sampling location (12°00′N, 135°00′E ) in western tropical Pacific Ocean and from 13 locations in the eastern area of the India Ocean ranging from 08°00′N-06°00′S and 86°00-76°00′E. Both the gap temperature for heat coma (GTHC, mean±SD: 7.83±1.86 °C, n=32) and the heat coma temperature (HCP, 35.03±1.80 °C, n=32) of individuals collected from the Pacific Ocean, during the first half (10 days) of the sampling period at the fixed sampling point, were significantly higher than those during the second half (GTHC: 5.10±2.05 °C, n=63; HCP: 34.03±2.02 °C, n=63). The reduction in heat tolerance shown in the second half of the 20 day period may have been caused by a decrease in air temperature due to rainfall that occurred around the sampling point accompanied with the arrival of Typhoon No. 6.In the study of individuals collected from the Indian Ocean, significantly higher average GTHCs of >8 °C were recorded for the adult H. micans collected at 02°00′S and 06°00′S (89°00′E) than those at 0°00-8°00′N in the eastern Indian Ocean. Dynamic mixture of water from northern and southern currents occurs at 02°00-6°00′S of the Indian Ocean and might relate to such high heat tolerance.Temperature dynamics in the ocean habitat might directly affect the temperature resistance of the oceanic sea skaters.  相似文献   

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7.
Song Y  Li Z 《ZooKeys》2012,(172):1-6
Seriana menglaensissp. n. (Hemiptera: Cicadellidae: Typhlocybinae: Erythroneurini) is described and illustrated from Southwest China. Seriana equata (Singh, 1969) is recorded for the first time from China.  相似文献   

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Dai R  Xing J  Li Z 《ZooKeys》2011,(82):67-72
This paper treats all four known species of the genus Neurotettix Matsumura, 1914 (Hemiptera, Cicadellidae, Deltocephalinae), including one new species: Neurotettix truncatussp. n. from China. A key is given to distinguish all species of the genus, and illustrations of genitalia are provided.  相似文献   

10.
Song Y  Li Z  Xiong J 《ZooKeys》2011,(83):57-62
In the present paper, a new species is added to the genus Diomma Motschulsky (Hemiptera: Cicadellidae: Typhlocybinae) from Southwest China, Diomma pincersasp. n. At the same time, a key can distinguish all Chinese species of the genus is provided.  相似文献   

11.
We examined morphological variation among populations of the stream-dwelling waterstrider, Aquarius remigis. A previous analysis of allozyme variation along a transect from southern Quebec to southern North Carolina revealed two distinct 'types' of A. remigis, north and south of a transition zone in southern New York and northern Pennsylvania. To assess the concordance of morphological and allozyme differentiation, adults were sampled from 15 populations along the original transect, as well as 11 additional populations in New York, Connecticut and New Jersey. Eight measurements of leg and body size were taken of preserved individuals. Univariate and multivariate analyses (multiple regression, PCA, discriminant analysis) reveal significant differentiation between northern and southern populations with a transition zone between latitudes 39oand 42onorth. Strong clines within each region and a clear transition between regions support previous suggestions that there are two distinct 'types' of this species in eastern North America. The transition zone, in morphology coincides with that revealed by the allozyme variation, but extends further south. The covariance of allozyme frequency and morphometric traits suggests that differentiation has occurred through vicariance and secondary contact, and that in this system, cladistic and adaptive differentiation are coupled.  相似文献   

12.
In this study we investigated the phylogenetic, morphological and ecological factors affecting the caw calls of 28 species of the genus Corvus, spanning the worldwide range of the taxon. The three phylogeographic groups identified by Goodwin (1986, Crows of the World, British Museum (Natural History), St Edmudsbury Press, Bury St Edmunds), i.e. the American stock, the Palearctic-African stock and the Oriental-Australian stock, were differentiated by some of the acoustic features of their calls, suggesting that historical factors may have played an important role in the evolution of vocalisations in this group. To assess the effects of morphology (body size and bill length) and environment (open vs. closed habitat) and to simultaneously take into account the phylogenetic effects, we used the phylogenetically independent contrast method. This manner of analysis revealed that body size was important in shaping the acoustic attributes of the caw call, as it influenced two temporal and two spectral variables, whereas the effect of bill length was far weaker. Notably, our results did not confirm the negative correlation between call frequency and body size that resulted in a phylogeny-free analysis of the same data in many studies on passerines. Larger Corvus species, in fact, utter calls with higher fundamental frequency than those of smaller species. Hence, these results show that incorporating phylogeny in analyses can substantially alter the conclusions reached by studies carried out with non-phylogenetic approaches. The acoustic environment, considered one of the most important forces driving the evolution of vocalisations in passerines, slightly influenced only two acoustic parameters in the Corvusgenus, call fundamental frequency and duration of pulsed units, both of which increased in the calls of forest species.  相似文献   

13.
Although the frequently large variance in relative male fertilizationsuccess when females are mated by more than 1 male has beenappreciated for some time, the factors that influence relativepaternity are still poorly understood. Recently, experimentalevidence that morphology of male genitalia influences fertilizationsuccess has been documented in 2 water striders, a dung beetle,and a leaf beetle. We explored the role of male genital morphologyin postcopulatory sexual selection in the oriental beetle. Wemated females to 2 males in succession and assessed relativepaternity by the sterile male technique. Morphology of the malegenitalia was found to strongly influence relative paternitybut only for the first male to mate. Male body size influencedrelative fertilization success as well, but again, only forthe first male; surprisingly, smaller males achieved higherpaternity when mating first. We also found suggestive evidencethat copula duration of both the first and second male to mateinfluenced paternity. Other factors, including female size anddegree of asymmetry of hind tibiae length of males had no effecton relative fertilization success. Our results for the orientalbeetle are novel among sperm precedence studies for 2 reasons:1) traits of the first male appear to be more important in influencingpaternity than those of the second, and 2) smaller, not larger,males achieved greater relative paternity. Our results alsocontribute to the growing body of empirical evidence in supportof the hypothesis that male genitalia evolve by postcopulatorysexual selection.  相似文献   

14.
Adelphocorisella lespedezae Miyamoto and Yasunaga, 1993 , which was previously known only from Japan, is reported from Korea for the first time and diagnosed. An image of its dorsal habitus as well as illustrations of the male genitalia are provided. The discovery of the mirid species also represents the first distributional record in Korea as well as the continental Palaearctic Region for the genus Adelphocorisella Miyamoto and Yasunaga, 1993 .  相似文献   

15.
A new hemipteran subfamily, Parastrachiinae , is proposed in the Cydnidae for the single genus Parastrachia Distant 1883. There are two included species, P. japonensis (Scott 1880) and P. nagaensis Distant 1908. The morphology, relationships, and taxonomic history of Parastrachia are discussed  相似文献   

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18.
Molecular phylogeny and evolution of the freshwater eel, genus Anguilla   总被引:3,自引:0,他引:3  
A molecular phylogenetic analysis was conducted on all of the known catadromous eel species of the genus Anguilla to assess their relationships and evolutionary history. The analyses of a total of 1427 bp of the mitochondrial 16S ribosomal RNA and 1140 bp of the complete cytochrome b gene sequences suggested that the genus Anguilla was monophyletic in origin, with A. borneensis as the most basal species. Four clades/species groups that correspond to their geographical ranges were indicated, Indo-Atlantic (three species), Oceania (two species), tropical Pacific (two species), and Indo-Pacific (five species), with ambiguous positions for A. japonica and A. reinhardti. This grouping conflicts with that of a previous morphological study, since the broad undivided maxillary and short-fin type, which were thought to be phylogenetically important, were paraphyletic in the molecular analysis. However, the molecular phylogeny and the present geographic distribution of species suggested historical dispersion of the genus Anguilla according to the Tethys corridor hypothesis, which proposed that anguillid eels originated near present-day Indonesia and dispersed westward along paleo-circumglobal equatorial currents. The westward-moving strain entered the paleo-Atlantic through the Tethys Sea and was ancestral to present-day European and American species.  相似文献   

19.
记述曲板叶蝉属Tautocerus Anufriev 1新种,望谟曲板叶蝉Tautocerus wangmoensis sp. nov..新种与齿突曲板叶蝉T. serristleus Zhang,Li et Qi相似,不同点是本新种头冠无黑色圆斑,雄虫尾节侧瓣端腹角有1枚小的乳状突,阳基侧突的外形明显不同.模式标本保存在贵州大学昆虫研究所.  相似文献   

20.
The Neotropical moth tribe Josiini (Notodontidae: Dioptinae) contains over 100 described species in 11 genera. All are diurnal, with brightly-coloured, presumably aposematic wing patterns. Larval hostplants are exclusively in the genus Passiflora (Passifloraceae) except for two new records, reported here, from Tumera (Turneraceae). A comparative morphological study of 26 representative josiine species yielded 86 characters from adults, larvae and pupae, all of which are figured and discussed. Phylogenetic analysis of these data produced a single most-parsimonious cladogram. According to the phylogenetic results: (1) monophyly of the Josiini is strongly supported; (2) the currently accepted generic classification is in disarray; (3) morphological character variation is extensive, and adult traits reflect phylogeny more effectively than do those of immature stages; (4) wing pattern types have undergone convergent evolution. A rare phenotype, longitudinal wing stripes, appears in two widely divergent clades, suggesting the evolution of Miillerian mimicry within the Josiini.  相似文献   

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