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1.
A new cave‐dwelling loach,Triplophysa xichouensis sp. nov. (Teleostei Nemacheilidae) from Yunnan,China
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A new cave‐dwelling loach of the genus Triplophysa, T. xichouensis, is described from an outlet of a subterranean river in Xisa Town, Xichou County, Yunnan Province, China. It can be distinguished from its congeners by the following characters: dorsal‐fin rays iii, 8; anal‐fin rays ii, 6; pectoral‐fin rays i, 9 or 10; pelvic‐fin rays i, 5 or 6; branched caudal‐fin rays 16(8+8); eyes highly degenerated to a very tiny black dot; dorsal‐fin origin closer to snout tip than to caudal‐fin base and anterior to vertical line of pelvic‐fin origin; pectoral fin length about two‐thirds the distance between pectoral‐fin origin to pelvic‐fin origin; caudal peduncle slender, its length about three times its depth; caudal fin emarginate; body smooth and scaleless; lateral line complete and straight; anterior chamber of air bladder wrapped in dumbbell‐shaped bony capsule and the posterior one well developed, long, oval; intestine short, bending in zigzag shape behind stomach. A key for the cave‐dwelling species of Triplophysa is provided. urn:lsid:zoobank.org:pub:9162FFB1‐7911‐47C3‐AE50‐6A00E9590327 相似文献
2.
A new species of deep‐living dragonet Callionymus omanensis from Oman is described on the basis of a single male specimen collected in a trawl from 500 m depth off the coast of Oman. The new species is characterized within the subgenus Bathycallionymus by having a small branchial opening; head short (3·9 in proportion to standard length); eye large (2·4 in proportion to head length); preopercular spine with a long, upcurved main tip, with a small antrorse barb and a larger antrorse spine, and with a strong antrorse spine laterally at the preopercular‐spine base, ventral margin smooth; first dorsal fin slightly higher than second dorsal fin (male); second dorsal fin distally straight; 17 pectoral fin rays; distal end of caudal fin slightly pointed, with two median unbranched rays bearing short filaments; first dorsal fin with basal black spot reaching from first to fourth membranes, third membrane with an ocellated distal black blotch; second dorsal fin with vertical dark grey bars; distal three‐fourths of anal fin black; upper half of caudal fin with oblique dark grey bars; pelvic fin dark grey, second ray basally with a black blotch. The new species is compared with similar species. Revised keys to callionymid species of the western Indian Ocean and the Red Sea, as well as species of the subgenus Bathycallionymus, are presented. 相似文献
3.
Francesco Cavraro Giulia Gheno Renzo Ganzerla Matteo Zucchetta Piero Franzoi Stefano Malavasi 《Ecology and evolution》2018,8(9):4422-4430
Display of bright and striking color patterns is a widespread way of communication in many animal species. Carotenoid‐based coloration accounts for most of the bright yellow, orange, and red displays in invertebrates, fish, amphibians, reptiles, and birds, being widely considered a signal of individual health. This type of coloration is under the influence of several factors, such as sexual selection, predator pressure, pigment availability, and light transmission. Fish offer numerous examples of visual communication by means of color patterns. We used a small cyprinodontid fish, Aphanius fasciatus (Valenciennes, 1821), as a model species to assess habitat constraints on the color display in male caudal fin. Populations from natural and open/closed artificial habitats were tested for differences in the pigmentation of caudal fins. The most important factors explaining the intensity of coloration were the habitat type and the chlorophyll concentration in the sediment, followed by water turbidity; yellow fins were observed in natural habitats with low chlorophyll concentration and high water turbidity, while orange fins occurred in artificial habitats with high chlorophyll concentration and low turbidity. Furthermore, A. fasciatus in artificial habitats showed a higher somatic and a lower reproductive allotment with respect to natural habitats, according to the existing literature on the species. Furthermore, in closed artificial habitats, where the most intense reddish coloration of caudal fins was observed, a trade‐off between somatic growth and the coloration intensity of a carotenoid‐based sexual ornament has been observed; in these populations, intensity of caudal fin coloration was negatively related to the somatic allotment. Results of this study suggested how both the pigmentation of male's caudal fin and the life history strategies of the species are constrained by habitat characteristics. 相似文献
4.
Age‐dependent decline in fin regenerative capacity in the short‐lived fish Nothobranchius furzeri
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The potential to regenerate declines with age in a wide range of organisms. A popular model system to study the mechanisms of regeneration is the fin of teleost fish, which has the ability to fully regrow upon amputation. Here, we used the short‐lived killifish Nothobranchius furzeri to analyse the impact of aging on fin regeneration in more detail. We observed that young fish were able to nearly completely (98%) regenerate their amputated caudal fins within 4 weeks, whereas middle‐aged fish reached 78%, old fish 57% and very old fish 46% of their original fin size. The difference in growth rate between young and old fish was already significant at 3 days post amputation (dpa) and increased with time. We therefore hypothesized that early events are crucial for the age‐related differences in regenerative capacity. Indeed, we could observe a higher percentage of proliferating cells in early regenerating fin tissue of young fish compared with aged fish and larger fractions of apoptotic cells in aged fish. Furthermore, young fish showed peak upregulation of several genes involved in fgf and wnt/β‐catenin signalling at an earlier time point than old fish. Our findings suggest that regenerative processes are initiated earlier and that regeneration overall is more efficient in younger fish. 相似文献
5.
Spawning aggregations in coral-reef fishes have been hypothesized to confer any one of several mutually non-exclusive benefits, largely expected to serve the interests of both sexes simultaneously. Here we provide indication that in the brown surgeonfish, Acanthurus nigrofuscus, spawning aggregations may confer a sex-specific benefit. Following tagged individuals en-route to their daily spawning-aggregation site we found that while migrating groups (≤20 fish) consist of both males and females, females tend to occupy the lead position more often than expected by chance. In addition, we found evidence that female A. nigrofuscus divide their daily egg-stock among several spawning bouts within the aggregations. We propose that female leadership en-route to spawning aggregations, together with the potential benefits of multiple female mating, are consistent with a sex-specific benefit to spawning aggregations. 相似文献
6.
A new species of Characidae, Moenkhausia celibela, is described from the Rio Amazonas at Santarém, Rio Maraú, several localities in the Rio Tapajós, Rio Curuá‐Una, Rio Xingu and Rio Jari, all from the Amazon basin, Brazil. The new species is distinguished from its congeners, except species included in Géry's 1992 Moenkhausia lepidura group, by presenting a dark blotch on the upper caudal‐fin lobe, and the lower lobe is hyaline or light grey. Moenkhausia celibela is distinguished from the species of the M. lepidura group by the absence of a humeral spot and the presence of a roughly triangular and dark spot at the caudal‐fin base, extending posteriorly along the middle caudal‐fin rays, and distinctly separate from the spot on the upper caudal‐fin lobe. 相似文献
7.
M. R. J. Morris E. Petrovitch E. Bowles H. A. Jamniczky S. M. Rogers 《Journal of fish biology》2017,91(2):645-663
Coastal marine Gasterosteus aculeatus were captured from seven locations along the Pacific coast of North America, ranging across 21·8° latitude to test Jordan's rule, i.e. that vertebral number should increase with increasing latitude for related populations of fish. Vertebral number significantly increased with increasing latitude for both total and caudal vertebral number. Increasing length with latitude (sensu Bergmann's rule) was also supported, but the predictions for Jordan's rule held when controlling for standard length. Pleomerism was weakly evidenced. Gasterosteus aculeatus exhibited sexual dimorphism for Jordan's rule, with both sexes having more vertebrae at higher latitudes, but only males showing a positive association between latitude and the ratio of caudal to abdominal vertebrae. The number of dorsal‐ and anal‐fin rays and basals increased with increasing latitude, while pectoral‐fin ray number decreased. This study reinforces the association between phenotypic variation and environmental variation in marine populations of G. aculeatus. 相似文献
8.
A new species of hillstream loach Balitora eddsi is described from the Karnali River drainage in south‐western Nepal. The new species is distinguished from all its congeners by possessing the following combination of characters: six to seven unbranched pectoral‐fin rays, pelvic‐fin length 12–14% standard length (LS), dorsal surface without circular or irregular shaped dark blotches, snout pointed, median lobe between anterior rostral barbels pointed posteriorly, dorsal‐fin origin posterior to pelvic‐fin origin, lateral line scales 66–67, caudal peduncle length 22–23·2% LS, caudal peduncle depth 4·1–4·2 times its length. 相似文献
9.
10.
Distribution and at‐sea behavior of Bermudan White‐tailed Tropicbirds (Phaethon lepturus catesbyi) during the non‐breeding season
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Miguel A. Mejías Yolanda F. Wiersma Jeremy L. Madeiros 《Journal of Field Ornithology》2017,88(2):184-197
The movements and behavior of many taxa of seabirds during the non‐breeding season remain poorly known. For example, although studies conducted in the Pacific and Indian oceans suggest that White‐tailed Tropicbirds (Phaethon lepturus) seldom fly more than a few thousand kilometers from nest colonies after breeding, little is known about the post‐breeding movements and behavior of a subspecies of White‐tailed Tropicbirds (P. l. catesbyi) that breeds on islands in the North Atlantic Ocean. Our objective, therefore, was to use light‐based geolocators to identify the ranges and pelagic activities of White‐tailed Tropicbirds from Bermuda during the non‐breeding periods in 2014–2015 (N = 25) and 2015–2016 (N = 16). Locations were estimated based on changes in light intensity across time, and pelagic activities were determined based on whether geolocators attached to leg bands were wet (i.e., birds resting on the water's surface) or dry (i.e., birds in flight). In 2014, birds spent late summer (July–September) near Bermuda and the British Virgin Islands; by mid‐September, most (N = 17; 68%) birds took a direct easterly route to the Sargasso Sea. In 2015, most post‐breeders (N = 15; 94%) flew east from Bermuda and to the Sargasso before the end of late summer. For both years combined, fall and winter (October–February) ranges extended as far west as North Carolina and as far east as the mid‐Atlantic Ridge. In both years, all birds were located between Bermuda and the British Virgin Islands during the spring (April–May). All birds then flew north to Bermuda in both years, with variations in timing, during April and May. We also found extensive overlap in the ranges of males and females during the non‐breeding season in both years. During the non‐breeding season, White‐tailed Tropicbirds spent 5% of night periods and 41% of day periods in flight in 2014; in 2015, birds spent 8% and 42% of night and day periods, respectively, in flight. Tropicbirds spent more time flying during the day because they hunt by day, detecting prey on the wing by sight. Overall, our results suggest that White‐tailed Tropicbirds that breed in Bermuda are diurnal, nomadic wanderers that range over an extensive area of the Atlantic Ocean during the non‐breeding season. 相似文献
11.
Combined results based on morphological characters and analyses of partial sequences of the 16s rRNA and coI genes confirm the validity of a new, cryptic, symphurine tonguefish from the western North Pacific Ocean. Symphurus leucochilus n. sp., a diminutive species reaching sizes to c. 67 mm standard length, is described from nine specimens that were collected from fish‐landing ports and from trawls made at c. 150 m off Taiwan and Japan. Symphurus leucochilus shares many similar features with those of Symphurus microrhynchus and that of several undescribed species that are morphologically similar to S. microrhynchus. Symphurus leucochilus has also been misidentified as Symphurus orientalis in fish collections because of shared similarities in some aspects of their morphology. The new species differs from all congeners by the following combination of meristic, morphological and pigmentation features: a predominant 1–2–2–2–2 pattern of interdigitation of proximal dorsal‐fin pterygiophores and neural spines; 12 caudal‐fin rays; 89–92 dorsal‐fin rays; 76–80 anal‐fin rays; 49–51 total vertebrae; four hypurals; 75–83 longitudinal scale rows; 32–35 transverse scales; 15–17 scale rows on the head posterior to the lower orbit; absence of a fleshy ridge on the ocular‐side lower jaw and a membranous connection between the anterior nostril and lower part of the eye; a narrow interorbital space and dorsal‐fin origin anterior to the vertical through the anterior margin of the upper eye; absence of both dermal spots at bases of anterior dorsal‐fin rays and melanophores on the isthmus; uniformly yellow to light‐brown ocular‐side colouration without bands; dorsal and anal fins with alternating series of dark rectangular blotches and unpigmented areas; a uniform white blind side and a bluish‐black peritoneum. Despite overall similarities in morphology between S. leucochilus and S. orientalis, as well as between two of the nominal species morphologically similar to S. microrhynchus, analyses of partial 16s rRNA and coI gene sequences show that S. leucochilus, S. orientalis and the two other nominal species represent three distinct lineages within the genus Symphurus. 相似文献
12.
Y. Iwatsuki 《Journal of fish biology》2013,83(1):64-95
Acanthopagrus latus, long considered a single valid Indo‐West Pacific Ocean species, characterized by having yellow pelvic, anal and caudal fins, is reviewed and separated into A. latus (east Asian shelf) and Acanthopagrus longispinnis (Bengal Bay), and three new species: Acanthopagrus morrisoni sp. nov. (north‐western Australia), Acanthopagrus arabicus sp. nov. [Middle East (except for the Red Sea) to coasts of Iran and Pakistan, and western Indian coast] and Acanthopagrus sheim sp. nov. (The Gulf). Although A. latus as redefined considerably varies in morphology and colouration, it can be recognized as a discrete east Asian endemic, with the following nominal species being junior synonyms: Chrysophrys auripes, Chrysophrys xanthopoda, Chrysophrys rubroptera and Sparus chrysopterus. Chrysophrys novaecaledoniae, known only from the holotype (type locality: Nouméa, New Caledonia), is a questionable junior synonym of A. latus, the lack of subsequent collections suggesting that the type locality is erroneous. Acanthopagrus longispinnis is differentiated from the other species in the complex by consistently having 12 dorsal‐fin spines and a much larger second anal‐fin spine, 21–26% (mean 23%) of standard length (LS) (v. 14–24%, mean 18–21% in the other four species). Acanthopagrus morrisoni sp. nov. has the entire caudal fin yellow with a wide black posterior margin (persisting in preserved specimens) and consistently 3 ½ scale rows between the fifth dorsal‐fin spine base and the lateral line. Acanthopagrus sheim sp. nov. has the pelvic, anal and lower caudal fins vivid yellow, with two (rarely three) small black blotches on the lower inter‐radial membranes between the spinous and soft dorsal‐fin rays. Acanthopagrus arabicus sp. nov. consistently has 4 ½ scale rows between the fifth dorsal‐fin spine base and the lateral line, whereas A. latus always has black streaks proximally on the inter‐radial membranes between the yellow anal‐fin rays. A neotype and lectotye, respectively, are designated for A. latus and A. longispinnis. The p‐distance (net nucleotide substitutions per site) of partial mitochondrial 16s ribosomal RNA genes (538 bp) among the above species (except A. longispinnis) and three other congeners (Acanthopagrus berda, Acanthopagrus pacificus and Acanthopagrus bifasciatus) strongly indicates that each is a distinct species. A key is provided for the 20 species of Acanthopagrus currently known from the Indo‐West Pacific Ocean. 相似文献
13.
The chick‐provisioning behaviour of the short‐tailed shearwater Puffinus tenuirostris and the wedge‐tailed shearwater Puffinus pacificus was investigated in a mixed colony on Montague Island, New South Wales, Australia, over two breeding seasons. This colony is located at opposite edges of the breeding distribution of the two species. Frequent weighing techniques were used to determine chick feeding frequency, feed timing, meal size, chick weight loss and indices of food conversion efficiency of the chicks. Short‐tailed shearwater parents fed their chicks larger more infrequent meals than wedge‐tailed shearwater parents. Short‐tailed shearwater chicks demonstrated higher food conversion efficiencies and lower weight loss than wedge‐tailed shearwater chicks, indicating either differences in diet or metabolic rates. The feeding frequency in wedge‐tailed shearwaters also fluctuated more widely than for short‐tailed shearwaters over the two breeding seasons. Despite the fact that the timing of the breeding cycle on Montague Island is almost identical for the two species, these differences in chick provisioning are probably a result of differences in prey type and location, so they may help explain variations in annual breeding success and limits to the distribution of the two species. 相似文献
14.
Caudal vertebral body articular surface morphology correlates with functional tail use in anthropoid primates
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Andrew S. Deane Gabrielle A. Russo Magdalena N. Muchlinski Jason M. Organ 《Journal of morphology》2014,275(11):1300-1311
Prehensile tails, capable of suspending the entire body weight of an animal, have evolved in parallel in New World monkeys (Platyrrhini): once in the Atelinae (Alouatta, Ateles, Brachyteles, Lagothrix), and once in the Cebinae (Cebus, Sapajus). Structurally, the prehensile tails of atelines and cebines share morphological features that distinguish them from nonprehensile tails, including longer proximal tail regions, well‐developed hemal processes, robust caudal vertebrae resistant to higher torsional and bending stresses, and caudal musculature capable of producing higher contractile forces. The functional significance of shape variation in the articular surfaces of caudal vertebral bodies, however, is relatively less well understood. Given that tail use differs considerably among prehensile and nonprehensile anthropoids, it is reasonable to predict that caudal vertebral body articular surface area and shape will respond to use‐specific patterns of mechanical loading. We examine the potential for intervertebral articular surface contour curvature and relative surface area to discriminate between prehensile‐tailed and nonprehensile‐tailed platyrrhines and cercopithecoids. The proximal and distal intervertebral articular surfaces of the first (Ca1), transitional and longest caudal vertebrae were examined for individuals representing 10 anthropoid taxa with differential patterns of tail‐use. Study results reveal significant morphological differences consistent with the functional demands of unique patterns of tail use for all vertebral elements sampled. Prehensile‐tailed platyrrhines that more frequently use their tails in suspension (atelines) had significantly larger and more convex intervertebral articular surfaces than all nonprehensile‐tailed anthropoids examined here, although the intervertebral articular surface contour curvatures of large, terrestrial cercopithecoids (i.e., Papio sp.) converge on the ateline condition. Prehensile‐tailed platyrrhines that more often use their tails in tripodal bracing postures (cebines) are morphologically intermediate between atelines and nonprehensile tailed anthropoids. J. Morphol. 275:1300–1311, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
15.
In two species of Heterodontus, H. portusjacksoni and H. galeatus, the first scales to develop form two opposing rows along the caudal fin axis on both the left and right sides of the fin. The opposing rows originate from an initial scale located on either side of the posterior tip of the caudal fin, with subsequent scales erupting in a posterior to anterior direction along the tail axis. These scale rows may strengthen tail movements, providing aeration in the egg case, but are lost later in ontogeny. Development of subsequent body scales shows a more irregular origin and arrangement, from anterior to posterior, to cover the dorsal and ventral lobes of the caudal fin. Although the early developmental pattern of the scale associated with the Heterodontus caudal fin has not been previously described, several chondrichthyan taxa, including chimeroids, likewise possess ordered rows of flank scales early in ontogeny that are subsequently lost. These ordered scales contrast with previous suggestions that chondrichthyan scale development is entirely random. Instead, regulated and sequential development of scales may be a plesiomorphic character for both chondrichthyans and osteichthyans, with the less organized arrangement in later ontogenetic stages being a derived condition within Chondrichthyes. 相似文献
16.
Previous research on the osteology of the Gobiesocidae focused mostly on the neurocranium and the thoracic sucking disc (formed by the paired‐fin girdles). Little attention has been paid to the skeleton of the median fins. The dorsal‐ and anal‐fin skeleton of Lepadogaster lepadogaster and other gobiesocids (excluding Alabes, which lacks these fins) are characterized by the absence of spines, branched fin‐rays, and middle radials. In gobiesocids, the distal radials never ossify and consist of elastic hyaline‐cell cartilage. Gouania wildenowi is unique among gobiesocids in having further reductions of the dorsal‐ and anal‐fin skeleton, including a notable decrease in the size of the proximal‐middle radials in an anterior–posterior direction. Unlike L. lepadogaster, which exhibits a one‐to‐one relationship between the dorsal‐ and anal‐fin rays and proximal‐middle radials, G. wildenowi has a higher number of proximal‐middle radials than distal radial cartilages and fin rays in the dorsal and anal fins. In G. wildenowi, the dorsal‐ and anal‐fin rays do not articulate with the distal tip of the proximal‐middle radials but are instead positioned between proximal‐middle radials, which is unusual for teleosts. Previously unrecognized dorsal and ventral pads of elastic hyaline‐cell cartilage are also present in the caudal skeleton of L. lepadogaster, G. wildenowi, and all other gobiesocids examined. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc. 相似文献
17.
In the larval bester, a hybrid sturgeon of beluga Huso huso and sterlet Acipenser ruthenus, development of cartilage around the notochord began 7 days post hatch (dph) (14·0 mm, total length, LT). The vertebral cartilage develops in the following sequence: basidorsals and basiventrals, neural canals, neural spines and ribs. The development of ribs remained incomplete in the largest specimen (181 dph, 179 mm LT) that was examined. Endoskeletal development of the fins began 4 dph for the dorsal and anal fins, 6 dph for the pectoral fin and 10 dph for the caudal and pelvic fins. Complete elements of all fins were observed by 91 dph and complete ossification of fin rays was observed by 122 dph in the double‐stained specimens. Observation of the histological sections, however, suggested that ossification occurred soon after the formation of the organic matrix in the fin rays. Dorsal scutes were first visible by 25 dph, followed by the lateral and ventral scutes, which were visible by 37 and 44 dph, respectively. The number of scutes was fixed at 44, 59 and 91 dph and ossification was complete by 59 (dorsal) and 91 dph (lateral and ventral scutes) in the double‐stained specimens. Ossification occurred soon after the formation of the scute organic matrix in the histological sections. Four types of scales were observed in the H. huso×A. ruthenus hybrid. Median predorsal, preanal and small scales on the anterior section of the head were visible by 59 dph. Scales on the caudal fin were visible by 91 dph and a variable assemblage of scales anterior to the anal fin was visible by 122 dph. Both the scutes and scales developed in a process that is similar to that of intramembranous ossification. 相似文献
18.
Year‐round movements of sympatric Fork‐tailed (Oceanodroma furcata) and Leach's (O. leucorhoa) storm‐petrels
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Luke R. Halpin Ingrid L. Pollet Christopher Lee Ken H. Morgan Harry R. Carter 《Journal of Field Ornithology》2018,89(3):207-220
Long‐distance movements are characteristic of most seabirds in the order Procellariiformes. However, little is known about the migration and foraging ranges of many of the smaller species in this order, especially storm‐petrels (Hydrobatidae). We used Global Location Sensors to document the year‐round movements of sympatrically breeding Fork‐tailed Storm‐Petrels (Oceanodroma furcata) and Leach's Storm‐Petrels (O. leucorhoa) from the Gillam Islands located northwest of Vancouver Island, British Columbia, Canada. In 2016, breeding Fork‐tailed (N = 5) and Leach's (N = 2) storm‐petrels traveled maximum distances of ~1550–1600 km from their colony to a region that has a wide shelf with major canyons creating a highly productive foraging area. After the breeding season, Fork‐tailed Storm‐Petrels (N = 2) traveled to similar areas west of the Gillam Islands, a maximum distance of ~3600 km from the breeding colony, and remained in the North Pacific Ocean and north of the Subarctic Boundary for an average of 5.4 mo. Post‐breeding Leach's Storm‐Petrels (N = 2) moved south to the Eastern Tropical Pacific, west of central Mexico, Ecuador, and northern Peru, an estimated maximum distance of ~6700 km from their breeding colony, and remained there for an average of 7.2 mo. Carbon (δ13C) and nitrogen (δ15N) stable isotope analyses of feathers revealed niche separation between Fork‐tailed (N = 21) and Leach's (N = 53) storm‐petrels. The wide range of δ15N values in the feathers of Leach's Storm‐Petrels (N = 53) suggests that they foraged at a variety of trophic levels during the non‐breeding season. Our results demonstrate that storm‐petrels have large core foraging areas and occupy vast oceanic areas in the Pacific during their annual cycle. However, given the coarse precision of Global Location Sensors, additional study is needed to identify the specific areas used by each species during both breeding and non‐breeding periods. 相似文献
19.
A. ROOME L. HILL V. AL‐FEGHALI C. G. MURNOCK J. A. GOODSELL R. SPATHIS R. M. GARRUTO 《Medical and veterinary entomology》2017,31(1):1-5
There is a public perception that the white‐tailed deer Odocoileus virginianus (Artiodactyla: Cervidae) is the main reservoir supporting the maintenance and spread of the causative agent of Lyme disease, Borrelia burgdorferi. This study examines the pathogen prevalence rate of Borrelia in adult Ixodes scapularis (Ixodida: Ixodidae), the black‐legged tick, collected from white‐tailed deer and compares it with pathogen prevalence rates in adult ticks gathered by dragging vegetation in two contiguous counties west of the Hudson Valley in upstate New York. In both Broome and Chenango Counties, attached and unattached ticks harvested from white‐tailed deer had significantly lower prevalences of B. burgdorferi than those collected from vegetation. No attached ticks on deer (n = 148) in either county, and only 2.4 and 7.3% of unattached ticks (n = 389) in Broome and Chenango Counties, respectively, were harbouring the pathogen. This contrasts with the finding that 40.8% of ticks in Broome County and 46.8% of ticks in Chenango County collected from vegetation harboured the pathogen. These data suggest that a mechanism in white‐tailed deer may aid in clearing the pathogen from attached deer ticks, although white‐tailed deer do contribute to the spatial distribution of deer tick populations and also serve as deadend host breeding sites for ticks. 相似文献
20.
A minimally invasive technique to assess several life‐history characteristics of the endangered great hammerhead shark Sphyrna mokarran
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A dorsal‐fin photo‐identification technique paired with a non‐invasive parallel laser photogrammetry technique was used to non‐invasively identify individual Sphyrna mokarran over time. Based on the data collected over a duration of 59 days, 16 different S. mokarran (mean ± s.d . pre‐caudal length: 220·82 ± 13·66 cm; mean ± s.d . cephalofoil width: 71·38 ± 7·94 cm) were identified using dorsal‐fin photo‐identification, with a mean ± s.d . shark re‐sighting frequency of 4·05 ± 3·06 at‐sea days. The results illustrate a high S. mokarran sighting rate and therefore, the utilization of parallel laser photogrammetry and dorsal‐fin photo‐identification may be a plausible multi‐year approach to aid in non‐invasively determining the growth rate and inter‐annual site fidelity of these animals. 相似文献