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1.
The fossil history of turtle and whale barnacles (Coronuloidea: Chelonibiidae, Platylepadidae, Coronulidae and †Emersoniidae) is fragmentary and has only been investigated in part. Morphological inferences and molecular phylogenetic analyses on extant specimens suggest that the roots of whale barnacles (Coronulidae) are to be found among the chelonibiid turtle barnacles, but the hard-part modifications that enabled early coronuloids to attach to the cetacean skin are still largely to be perceived. Here, we reappraise a fossil chelonibiid specimen from the Miocene of insular Tanzania that was previously referred to the living species Chelonibia caretta. This largely forgotten specimen is here described as the holotype of the new species †Chelonibia zanzibarensis. While similar to C. caretta, †C. zanzibarensis exhibits obvious external longitudinal parietal canals occurring in-between external longitudinal parietal septa that abut outwards to form T-shaped flanges, a character so far regarded as proper of the seemingly more derived Coronulidae and Platylepadidae. Along with these features, the presence of a substrate imprint on the shell exterior indicates that †C. zanzibarensis grasped its host's integument in much the same way as coronulids and platylepadids, albeit without the development of macroscopic parietal buttresses and bolsters. Thin section analyses of the inner parietal architecture of some extant and extinct coronuloids conclusively demonstrate that vestiges of comparable external parietal microstructures are present in some living members of Chelonibiidae. This observation strengthens the unity of Coronuloidea while significantly contributing to our understanding of the evolution of the coronuloid shell structure in adapting to a diverse spectrum of hosts.  相似文献   

2.
Extract

Madam: — In June 1986, I was called to a piggery in the West Auckland area. The piggery consists of a breeding and fattening unit. Piglets from two hundred sows are taken through to pork and bacon weight. All pigs are meal fed. The dry sows and farrowing unit are separated within the same building. The weaners and fatteners are in two separate buildings in close proximity. Boars and gilts are brought in from more than one source.  相似文献   

3.
Abstract

Thorn length and density on the latest year's growth were compared at three height (feeding) levels (<1m, >1m<2 m and >2 m) on individuals of Acacia karroo and Ziziphus mucronata in an area that was browsed by goats. Thorn length and density was greatest for branches within easiest reach of goats. However, there was no increase in thorn length or density on the latest year's growth of branches of A. karroo individuals protected from browsing. Thorns on distal ends of branches are relatively small and sparse and this is partly due to differences in internode length. Herbivores limit the extent of annual growth and this prevents development of small thorns characteristic of late season growth. Thus, browsed individuals which lack late season growth may have greater spinescence. This is only a passively induced response and is not due to the active production of larger thorns subsequent to browsing.  相似文献   

4.
Uniformitarianism permits understanding of the past on the basis of the present, and modeling the future through consideration of the fossil record. The present paper addresses the impact environmental (climatic) change has had on acorn barnacles and eucalyptus trees. Acorn barnacles (Balanomorpha) are first recorded after the K/T mass-extinction event. In the Paleogene, rapid radiation resulted in their occupying most marine environments. That balanomorphs survived both the Paleocene–Eocene thermal maximum and the Pleistocene glaciation is testament to their ability to adapt to opportunities; they are known from the littoral (Chamaesipho) to depths of 3600 m (Tetrachaelasma) and within this from diverse substrates: rock, wood and miscellaneous flotsam, plus in symbiosis or commensalism with most larger marine organisms. Darwin's (1854) view of the late Tertiary as the age of barnacles is reflected in their diversity, distribution and biomass. Barnacles are contrasted with the Australian Myrtaceae: plants ranging from woody shrubs to tall trees. The most significant is Eucalyptus sensu lato, which typifies Australia's flora, and is characterized by aromatic leaves that produce eucalyptol. Eucalyptus has evolved strategies that result in its domination of Australian open woodlands: these include production of highly flammable eucalyptol oil (with a flashpoint of 49 °C) and an unprecedented ability to regenerate following forest fires. Gum trees and barnacles first appear in the Paleogene, their earliest records are Australasian, and they both demonstrate extraordinary resilience when environmental conditions are optimal.  相似文献   

5.
Abstract

Unusual short-term associations provide insight into the long-term development or modification of parasitism. A superinfestation of a trap-held crevalle jack Caranx hippos by juvenile cymothoid isopods Cymothoa oestrum suggested loss of the mechanism controlling numbers of isopods on a host, and overcrowding on the host overcame this isopod's strict site specificity. Crabs (Decapoda) have not been reported as parasites of fishes, but unidentified crab zoeae superinfested the gills of a trap-held gray angelfish Pomacanthus arcuatus. Adult burrowing crabs Raninoides lamarcki invaded the gills of trap-held gray snapper Lutjanus griseus; this suggested how a relatively large crustacean could become an opercular chamber parasite and how wound feeding could occur. An apparent prey-to-predator transfer of the cymothoid isopod Anilocra acuta to a free-swimming king mackerel Scomberomorus cavalla also represented a move from an external to a pharyngeal-attachment position in this site-specific isopod. Trap confinement may have protected the infestations of juvenile C. oestrum and crab zoeae from organisms that serve as cleaners. New associations are usually begun by immature stages, but may also be initiated by adult crustaceans, as in the cases of A. acuta and R. lamarcki. The ability of crustaceans to survive, adapt, and be observed makes them excellent subjects for use in discerning complex parasitological processes.  相似文献   

6.
Burchell's redfin, Barbus burchelli is endemic to the Breede River and adjacent smaller river systems in the Cape Province. Negative human influences have led to a drastic decline in numbers of this medium-sized minnow, especially agricultural demand on the water resource and the introduction of exotic predatory fish. The breeding season is extended, from September to February, with a peak in December. The absolute fecundity of a 123 mm FL specimen was 10 678, which includes both mature and recruitment ova. Females grow larger (123 mm FL), and live longer (6 +years), than males (113 mm FL and 4 + years). 8. burchelli grow rapidly in their first year attaining a length of between 40 and 50 mm FL. Pronounced conical tubercles of sexually mature males erupt in spring, begin to show signs of wear in November and by March are worn or sloughed off. The survival of this species is dependent upon proper management of the Breede River system.  相似文献   

7.
South Africa urgently requires a national strategic plan for the conservation of the country's biodiversity. The formulation of such a plan would be relatively easy if centres (hotspots) of richness, endemism and rarity were congruent, both within and among many different taxa, if these hotspots captured a large proportion of the total species, and if hotspots fell within existing reserves. The investigation of six vertebrate taxa (vizfreshwater fish, frogs, tortoises and terrapins, snakes, birds, and various mammal orders) at a national scale reveals that hotspots are not coincident within taxa. Centres of richness are concentrated in the north-eastern areas of the country, whereas endemism is concentrated in the south-west, and centres of rare and threatened {Red Data Book) species can be in either area. Paired comparisons among taxa reveal greatly varying proportional overlaps of species richness hotspots (0-72%). The proportion of total species falling in hotspots ranges from low (66% for fish) to high (92% for birds). Hotspots are thus not an efficient method of siting representative (ideal) reserves. In order to design a more representative reserve system to protect all vertebrate species, a complementarity algorithm was applied to all taxa separately, and then to all taxa combined. The combined analysis yielded more efficient results {66 reserves are required to represent all 1074 species at least once) than the separate analyses (97 reserves). Many of these representative reserves coincide with both hotspots and existing reserves, and over 85% of the hotspots of most taxa coincide with existing reserves, thus South Africa's vertebrate fauna could be more effectively protected with only moderate acquisition of new, well-sited reserves. A biome analysis reveals that these reserves will also have to incorporate areas of those biomes that are currently inadequately protected, viz grassland, Succulent Karoo and Nama-Karoo. The methods outlined in this paper should be applied to as many other taxa as possible, in order to aid the formulation of a national strategic plan for biodiversity conservation.  相似文献   

8.
动物标本是野生动物研究的基础材料,大部分国家公园和自然保护区都有自己的标本馆,收集和储存标本供参观和研究所用。标本的采集、记录、制作和保存是野生动物管理人员的一项基本技能,每位管理人员都应掌握。不管是皮张、头骨、角或牙齿都是很好的标本。对保护动物的采集,必须得到管理部门的许可。黄腹角雉标本的制作尤为重要,作为国家Ⅰ级保护动物,它更加具有科研和观赏价值。  相似文献   

9.
Objective To compare the results of radiometric culture conducted in three Australian laboratories for Mycobacterium avium subsp. paratuberculosis (Mptb) using bulk vat and individual animal milk samples. Procedure Milk samples were collected from 15 cows exhibiting clinical signs of Johne's disease, and subsequently confirmed as infected with Mptb, and from the bulk milk vats on 91 farms running herds known to be infected with Mptb. Each milk sample was divided into three equivalent samples and one of each of the replicates was forwarded to the three participating laboratories. The identity and nature of the samples was protected from the study collaborators. The laboratories processed the samples and undertook radiometric culture for Mptb using their standard method. Results of testing were provided to the principal investigator for collation and analysis. Results In total, 2 (2.2%) of 91 vat-milk samples and 8 (53.3%) of 15 individual cows' milk samples returned positive radiometric milk culture results. Only one sample, from a clinical case of Johne's disease, was identified as positive by more than one laboratory. There were differences in the absolute frequency with which Mptb was identified in the milk samples by the collaborating laboratories. Conclusions Mptb was cultured from a very small percentage of Australian raw bulk milk samples sourced from known infected herds. By contrast, Mptb was successfully cultured from half of the milk samples collected from clinically affected cows. There was no statistical difference between laboratories in the proportion of vat samples or individual animal milk samples in which Mptb was detected.  相似文献   

10.
The leading direct cause of the loss of biodiversity is habitat alteration and disruption. If we are to address this cause directly, we need to find ways of changing the behavior of rural people. Experience has shown that this is done most effectively through the use of economic instruments, ranging from taxes that discourage over‐exploitation, to direct payments for conservation activities carried out by rural land‐owners or those occupying the land. In many parts of the world, governments provide incentives such as tax breaks to private land‐owners. Other countries recognize specific use rights on particular parts of the land, enabling the land‐owners to earn appropriate benefits. Since many protected areas have resident human populations, it is especially important that they be encouraged to contribute to the objectives of the protected area, and economic incentives offer an important way of doing so; they might, for example, be given employment in the protected area or in associated tourism activities. Direct payments to farmers for conserving watersheds is becoming increasingly popular, in both developed and developing countries. Improved conservation will require both removing perverse subsidies and developing a wide range of approaches for rewarding land‐owners for biodiversity conservation activities.  相似文献   

11.
现代楼房养猪智能化环境控制及疾病预防技术概述   总被引:1,自引:0,他引:1  
如今,非洲猪瘟的疫情对国内养猪行业影响巨大,猪场的生物安全备受关注,我国的养猪模式在此基础上发生了改变,由原来的小户散养逐渐转型为集约化、集团化养殖;近年来,国家对土地资源的管控使得养殖用地愈发紧张,我国对猪肉的高需求量得不到满足,“楼房养殖”这一概念逐渐被推出到大家的视野中。文章主要分析了楼房养殖的现状、优势、痛点的问题;并对楼房养殖的智能化环境控制和疾病预防技术进行介绍。  相似文献   

12.
Based on strandings and captures, 9 cetacean species, including 6 odontocetes and 3 mysticetes, are documented (photos and specimens) in Togo's coastal waters (newly‐recorded species marked with an asterisk): Antarctic minke whale (Balaenoptera bonaerensis*), Bryde's whale (Balaenoptera brydei or B. edeni), humpback whale (Megaptera novaeangliae), sperm whale (Physeter macrocephalus), pygmy sperm whale (Kogia breviceps*), short‐finned pilot whale (Globicephala macrorhynchus*), pantropical spotted dolphin (Stenella attenuata*), common bottlenose dolphin (Tursiops truncatus) and common dolphin Delphinus sp. An anecdotal sighting record for killer whale (Orcinus orca) is considered reliable. The lack of Sousa teuszii records in Togo is consistent with its apparent contemporaneous absence in Ghana. The B. bonaerensis specimen, entangled in a purse seine set on small pelagics, is a first record for the Gulf of Guinea. The occurrence of this Southern Ocean species north of the equator underscores the severe gaps in our understanding of cetacean distribution off western Africa. The majority of artisanal fishermen operating in Togolese coastal waters are of Ghanaian origin and are thought to promote trade and consumption of cetacean bushmeat. Because captures are illegal, enforced with some success in the main fishing centers, covert landings of cetaceans are exceedingly difficult to monitor, quantify or sample. Concern is expressed about pollution of Togo's coastal waters with heavy metals due to phosphorite mining and export from the coastal basin near Hahotoé and Kpogamé.  相似文献   

13.
The sprawl of the urbanization and road network process without building ecological corridors contributes to the high mortality rates and a threat to the population decline of wild species such as the crab‐eating fox. A strategy for the ex situ conservation is the study of the reproductive biology of the species and cryopreservation of their genetic heritage through the formation of an animal germplasm bank. This research is in accordance with the principles adopted by Brazilian College of Animal Experimentation. Reproductive systems of Cerdocyon thous females (n = 7) were examined macroscopically and microscopically by histological techniques and scanning electron microscopy. Gross features showed the shape of the ovaries was similar to a bean, and the elongated oviducts lengths were between 5 and 8 cm, with body of the uterus (3 cm) with long and narrow uterine horns (9–11 cm). The cervix was as a single annular conformation carrying out communication between the uterus and the vagina. The vagina has lengthened and circular muscle and the vulva with dense anatomical conformation with a quite pronounced clitoris. In addition, with regard to the establishment of a cell line (fibroblasts) for the gene bank enrichment, cells showed a low clonogenic capacity, especially when compared to domestic dogs, which can be explained by “in vitro” environment, age and diet of the animal. However, it was possible to create a bank of limited cell number. This study had morphological and preservationist character and aimed to help at long term in the conservation of wild animal's genetic resources.  相似文献   

14.
15.
Rinderpest had been reported in most parts of Ethiopia when the Pan African Rinderpest Campaign (PARC) was launched. As a result of intensive disease investigation and strategic vaccination, most parts of the country are now considered provisionally free, and widespread vaccination has been replaced by clinical and serological surveillance. Details of any episodes of disease are recorded and followed up after laboratory confirmation of suspected cass using antigen-capture ELISA. This paper is based on observations on the performance of the antigen detection ELISA compared to the agar gel immunodiffusion (AGID) test, which also differentiates rinderpest from peste des petits ruminants (PPR). The stability of the specific viral antigen was monitored for 4 days, and rinderpest and PPR antigens were still detected, depending on the type of specimen. Antigen capture ELISA is more rapid, sensitive and virus specific than the AGID. Even if the cold chain of the specimen is compromised for a day or two during sample collection and submission, the specimen may still be suitable for testing by ELISA.  相似文献   

16.
我国纺织类非物质文化正面临衰退和变异。高等学校纺织类专业具有雄厚的学科背景、完善的实验研究条件、大量专业人才等显著优势,可以通过挖掘、整理优秀纺织类非物质文化遗产资源,加强师资队伍建设,构建纺织类非物质文化遗产融入现代纺织高等教育的载体与平台,为其有效保护、传承和利用开辟一条新的途径。  相似文献   

17.
马莉贞 《草业科学》2012,29(12):1832-1841
通过文献和标本记录分析得到青海省珍稀濒危保护植物的种数,并尽可能得到它们在青海省的具体分布地,结合ArcGIS的手段,进一步了解并核实这些珍稀濒危保护植物在青海省各州(市、县)的分布情况。结果表明,青海省珍稀濒危保护植物在全省各州(市)均有分布,物种丰富度最高的是玉树州,有73种,占总物种数的50%;物种丰富度最低的是海西州,有26种;珍稀濒危保护植物在全省各县的分布差异很大,其中玉树县有57种,而甘德县只有5种。本研究可为青海省珍稀濒危保护植物的保护研究和开发利用提供一定的理论依据。  相似文献   

18.
Intervertebral disc disease, as well as the associated alteration of the radiographic intervertebral disc space width, has been reported in horses. Disc height index (DHI) has proven to be an accurate and objective parameter in other species but data related to this parameter are lacking in horses. Therefore, the aims of this retrospective longitudinal diagnostic accuracy study were (a) to evaluate the reliability of measurements within and between observers of the equine Disc Width Index (EDWI) as a parameter for radiographic equine cervical intervertebral disc space width, and (b) to evaluate the sequential development of the EDWI over time. For this, EDWI from all intervertebral disc spaces between second cervical (C) to first thoracic (Th) vertebrae were obtained in a group of 39 Dutch Warmblood horses at 1, 5, and 18 months of age, by one European College of Veterinary Diagnostic Imaging (ECVDI) board‐certified veterinary radiologist (S.V.) and two veterinary students. Bland‐Altmann plots and intraclass Correlation Coefficient revealed a good intra‐ and interobserver agreement. A linear mixed‐effect model did reveal that mean EDWI increases significantly toward the caudal cervical spine, but did not differ significantly for a certain location over time or between sexes. Spearman's rank test did show a significant correlation between the vertebral alignment angle induced by different head‐neck positions and a normalized EDWI (ρ = 0.33, P < .0001). Student's t‐test revealed that the presence of C6‐C7 transposition of the transverse processes did not influence EDWI significantly. It was concluded that EDWI represents a reliable parameter for equine cervical radiographic intervertebral disc space width. Practical implementation of EDWI warrants monitoring in a group of adult horses while maintaining a standardized head‐neck position.  相似文献   

19.
A 5‐year‐old male neutered reindeer (Rangifer tarandus tarandus) from Missouri was presented with a 3‐week history of anorexia, respiratory distress, lethargy, and weight loss. Blood smear review revealed that a small percentage of RBCs contained small (1–2 μm in length) pleomorphic piroplasms (signet ring, rod‐ or pear‐shaped, and elongate forms) with an eccentric magenta nucleus and basophilic cytoplasm. Nested PCR to specifically amplify a portion of the piroplasm small subunit ribosomal RNA (SSU rRNA) gene was performed on DNA extracted from an EDTA specimen of whole blood. Subsequent sequence analyses showed similarity between the reindeer hemoparasite and Theileria spp SSU rRNA gene sequences in the GenBank database, with highest similarity to those of a Theileria sp in a White‐tailed deer from North Texas (AY735132, AY735133). The reindeer and North Texas Theileria sp are genetically distinct from, albeit closely related to, the White‐tailed deer Theileria sp (subsequently referred to as T cervi). To the authors' knowledge, this is the first identification of Theileria of this genotype in a reindeer. Historically, T tarandirangiferis infection was found with associated mortality in reindeer in Russia, but reports predate molecular characterization. Hence, the relationship of T tarandirangiferis with either T cervi or this agent remains unknown. T cervi is not typically pathogenic in White‐tailed deer in the US unless the animal is immune‐compromised by stress or disease; however, mortality from T cervi infection in reindeer has been reported.  相似文献   

20.
This report concerns a collection of parasitic worms from South Africa, and contains a new species of monogenean, Gyrodactylus transvaalensis, six species of adult trematodes, including a new species of Phyllodistomum.P. van der waali, two metacercariae of the Family Clinostomidae and three of the Order Strigeida, as well as two species of cestodes, and larvae of the nematode genus Contracaecum. The adults of previously-known helminths are redescribed, with some remarks on their systematics and biology. Accompanying the material of the new gyrodactylid monogenean there is a specimen which is thought to be a giant of the new form, and this appears to be the first recorded suggestion of the occurrence of gigantism in the Monogenea, and in fact in any kind of helminth.  相似文献   

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