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1.
The dermal layers of several elasmobranch species have been shown to be sexually dimorphic. Generally, when this occurs the females have thicker dermal layers compared to those of males. This sexual dimorphism has been suggested to occur as a response to male biting during mating. Although male biting as a copulatory behaviour in Scyliorhinus canicula has been widely speculated to occur, only relatively recently has this behaviour been observed. Male S. canicula use their mouths to bite the female’s pectoral and caudal fins as part of their pre-copulatory behaviour and to grasp females during copulation. Previous work has shown that female S. canicula have a thicker epidermis compared to that of males. The structure of the dermal denticles in females may also differ from that of males in order to protect against male biting or to provide a greater degree of friction in order to allow the male more purchase. This study reveals that the length, width and density of the dermal denticles of mature male and female S. canicula are sexually dimorphic across the integument in areas where males have been observed to bite and wrap themselves around females (pectoral fin, area posterior to the pectoral fin, caudal fin, and pelvic girdle). No significant differences in the dermal denticle dimensions were found in other body areas examined (head, dorsal skin and caudal peduncle). Sexually dimorphic dermal denticles in mature S. canicula could be a response to male biting/wrapping as part of the copulatory process.  相似文献   

2.
Gary J. Samuels 《Brittonia》1988,40(3):306-331
Nine species ofNectria are described or redescribed. Ascospores of all are colorless and striates; their perithecia are orange and do not become red in KOH. Three groups of species are represented. One group includesNectria grammicospora, N. cf.grammicospora, N. subquaternata, and the new species:N. grammicosporopsis, N. lucifer, andN. neogrammicospora. A second group includes the new speciesN. chlorogloea andN. septomyrotheciae. The third group is represented by the single new speciesN. dacryocarpa. The life-cycles of these species are described. Anamorphs ofN. grammicospora, N. grammicosporopsis, N. lucifer, andN. subquaternata are species ofClonostachys. The anamorph, ofN. neogrammicospora isAcremonium- orCephalosporiopsis-like in having monophialidic conidiophores and phragmosporous conidia, and that ofN. cf.grammicospora isAcremonium-like with amerosporous conidia. The anamorphs ofN. chlorogloea andN. septomyrotheciae have green conidia. The anamorph ofN. chlorogloea isMyrothecium sp.; its conidia are unicellular and the conidioma is a synemma. The anamorph ofN. septomyrotheciae isSeptomyrothecium cf.uniseptatum; its conidioma is a sporodochium and the conidia are bicellular. The new genus and speciesDacryoma alba are described for the anamorph ofN. dacryocarpa. All of these fungi are pantropical or Australasian in distribution.  相似文献   

3.
Mimosa biuncifera, as currently defined in southwestern United States, is shown to comprise two related species,M. biuncifera s. str. andM. texana, distinguished primarily by position of the nodal aculei. Taxonomic synonyms ofM. biuncifera areM. lindheimeri andM. warnockii (the first undisputed, the second provisional);M. texana includesM. wherryana.  相似文献   

4.
5.
Larval development ofOdontobutis obscura obscura, reared withArtemia sp. andLimnodrilus sp. for about two months, was observed in a room maintained at 20±0.5°C. The development was classified into nine nominal stages, and was compared with that ofO. o. interrupta and ofO. platycephala. The size and shape of the eggs and the development of this species are similar to those ofO. o. interrupta andO. platycephala. From the juvenile stage,O. obscura is distinguishable fromO. platycephala by the appearance of dark bands on the body located in the same position as in adults.O. o. interrupta is also distinguished fromO. o. obscura in the juvenile stage by the presence of melanophores on the dorsal and ventral sides of the caudal peduncle. The anal fin fold ofO. obscura is higher than the dorsal fin fold, but the two folds are equal in height inO. platycephala. O. obscura has a well-developed air bladder and swims high in the water at the feeding stage.O. platycephala has a poorly developed air bladder and swims on the bottom. Xanthophores are observed at an earlier stage and more strongly developed inO. obscura than inO. platycephala. Growth rate is faster inO. obscura than inO. platycephala. O. obscura spawns at a smaller body size thanO. platycephala. InO. o. obscura, the arrangement of cephalic pit organs is completed at 14 mm SL. InO. o. interrupta, this arrangement is completed at the same time or a little later than inO. o. obscura. The infraorbital and verticalantorbital pit lines ofO. platycephala, which are separated in the adults, are connected until the juveniles measure about 30 mm SL. These pit lines are connected even in the adults ofO. o. obscura andinterrupta. InO. platycephala, the sensory canals are first formed behind the eyes, then dorso-anterior to the eyes, then at the posterior edge of the preopercles and finally anterior to the eyes. Postocular canals begin to form in individuals more than 20 mm SL. All individuals ofO. o. interrupta more than 70 mm SL have postocular canals.O. o. obscura has no sensory canals throughout life. The differences in growth rate, body size at spawning, and the time of completion of the cephalic lateral line system suggest paedomorphosis in the three taxa studied here.  相似文献   

6.
The so-calledOryzias melastigma (McClelland, 1839), reported from India, Bangladesh, Myanmar, and Malaysia by numerous authors beginning with Day (1877), is based mainly or entirely onAplocheilus panchax (Hamilton, 1822). India and Bangladesh have two species ofOryzias, both large. The deeper-bodied of these two species is reported for the first time asO. dancena (Hamilton, 1822). The other is identified asO. carnaticus (Jerdon, 1849). Myanmar has one large species,O. dancena, and one tiny species,O. uwai new species.Oryzias minutillus Smith, 1945 andO. uwai differ from all otherOryzias in having 4/5 instead of 5/6 principal caudal fin rays.Oryzias uwai differs fromO. minutillus in being more conspicuously pigmented and having large, 6-rayed pelvic fins often extending to anal fin origin instead of much smaller and shorter 5-rayed pelvic fins. In Thailand (including its part of the Mekong basin) three species are known: a large estuarine species tentatively identified asO. javanicus (Bleeker, 1854) and two tiny inland species,O. mekongensis Magtoon & Uwa, 1986, andO. minutillus. Oryzias minutillus from many localities are more or less melanoproctic, i.e. have a darkly pigmented genital or vent area not seen in other species. The Mekong basin in Laos has two large species,O. latipes (Temminck & Schlegel, 1846) andO. pectoralis new species, distinguished by a prominent black blotch on the pectoral fin base, both recently collected in the Nam Theun watershed in central Laos; and two tiny species,O. mekongensis andO. minutillus. Only one species ofOryzias is known from the Mekong delta in Vietnam, the small moderately deep-bodiedO. haugiangensis new species, with 19–22 anal and 9–10 pectoral fin rays. The Indonesian island of Java has one large species,O. javanicus (Bleeker, 1852) with 21–25 anal and 11 pectoral fin rays, and one small species,O. hubbsi new species, with only 17–21 anal and 9 pectoral fin rays.  相似文献   

7.
A revision of the surviving “Barroisiceras” specimens from Cameroon described by SOLGER (1904) suggests thatBarroisiceras brancoi, type species ofSolgerites REESIDE, 1932, including varietiesmitis andarmatus of SOLGER, andBarroisiceras hoberfellneri alstadenensis SOLGER non SCHLüTER are variants of a single species and thatSolgerites is a synonym ofForresteria (Forresteria) REESIDE, 1932, of whichEboroceras BASSE, 1947 also is a synonym.  相似文献   

8.
The dental and cranial morphologies of all species ofSaguinus, S. oedipus, S. geoffroyi, S. leucopus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S. bicolor, andS. midas are examined. The following hypotheses are developed by cladistic methodology, using only synapomorphic characters to assess the interspecific relationships ofSaguinus.Saguinus are divided into two main groups; one consists ofS. oedipus, S. geoffroyi, andS. leucopus, and the other includesS. inustus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S. bicolor, andS. midas. In the former group,S. oedipus is more closely related toS. geoffroyi than either is toS. leucopus. In the latter group,S. labiatus, S. mystax, andS. imperator are classified into one group, andS. bicolor andS. midas form one monophyletic group.  相似文献   

9.
A new aulopodid fish,Hime microps, is described after two specimens from the Nazca submarine ridge (25°43′S, 85°29′W at 160–165 m; 25°42′S, 85°24′W at 162–168 m). This species is related toH. japonica andH. curtirostris but differs in having no pyloric caeca and smaller eyes with the horizontal diameter shorter than the snout length. Specimens ofH. japonica from off Japan, the Hawaiian submarine ridge and the Tasman Sea are compared and found to be morphologically identical.  相似文献   

10.
A new genus and species of the Paroxyclaenidae is described,Merialus martinae, and the family is reviewed and divided into two subfamilies, the Paroxyclaeninae and the Merialinae, new. The two species ofDyspterna are attributed to two genera, of whichEuhookeria is new; Dyspterninae Kretzoi, 1943, is resurrected to includeDyspterna woodi, Cryptopithecus andKochictis; the subfamily is referred to the Pantolestidae.Vulpavoides is considered valid and includes“Russellites” simplicidens;V. vanvaleni n. sp. is described from Bouxwiller.Kiinkerishella andDulcidon are discussed, as are possible relationships between the Ptolemaiidae and the Merialine paroxyclaenids.  相似文献   

11.
A new genus,Siemensichthys, from the Upper Jurassic of southern Germany is described. The new genus includes two species,S. macrocephalus (Agassiz) which was formerly in the genusPholidophorus, andS. siemensi n. sp. The two species share synapomorphies such as only one supramaxillary bone covering the dorsal margin of the maxilla. Both species are described, and their phylogenetic position is analyzed. The phylogenetic analyses, based on 27 taxa and 141 characters, show thatAnkylophorus from the Kimmeridgian of Cerin,Siemensichthys andEurycormus from the Solnhofen Lithographic Limestone of Bavaria, form a monophyletic group. The new extinct clade (preliminarily identified as theSiemensichthys- group) is proposed as the sister-group ofPholidophorus s. str. plus more advanced teleosts. This sister-group relationship is supported by eight characters (e.g., supraoccipital bone extending forward in the roof of the otic region; articular bone fused with both the angular and retroarticular; presence of an elongated posteroventral process of quadrate; presence of dorsal processes at the base of the innermost caudal rays of upper lobe; mobile premaxillary bone). Comparisons with species ofPholidophorus s. str. provide a new understanding of the genusPholidophorus. At least four synapomorphies are proposed to support the monophyly ofPholidophorus. As a consequence of this new interpretation, the European Late Jurassic species previously assigned to the Pholidophoridae and to the genusPholidophorus (e.g., ‘Ph.’armatus, ‘Ph.’ falcifer, ‘Ph.’ micronyx, ‘Ph.’ microps) should be reexamined because they do not belong to the family nor to the genus. The order PholidophoriformesBerg is not a monophyletic group as currently constructed. Therefore, all so-called pholidophoriforms are in need of revision.  相似文献   

12.
R. J. Milner 《BioControl》1973,18(4):383-390
A dose-mortality technique was used to compare the pathogenicity ofNosema whitei for 4 stored products pests.Tribolium castaneum, T. confusum andOryzaephilus surinamensis were similar in susceptibility, whileT. anaphe was at least 100 times more susceptible. A possible explanation for this difference is thatT. anaphe has a much longer developmental time (28 days at 25°C) than the other 3 species (20 days at 25°C). The host range was studied in another 8 species from 2 orders.T. brevicornis, T. destructor, andT. madens were all susceptible while the other species tested (includingTenebrio molitor, Palorus ratzburgi andPlodia interpunctella) were refractile to infection.  相似文献   

13.
Larval developments ofPempheris xanthoptera andP. japonica were described on 31 (6.45–22.40 mm SL) and 5 (10.35–35.70 mm SL) specimens, respectively, with particular attention to cartilaginous development. Comparison between the two species indicated thatP. xanthoptera was discriminated fromP. japonica by the following key characters: two supracleithral spines (one inP. japonica); longer pectoral fin; shorter ventral fin; and absence of melanophore on mid-ventral part of lower jaw and anterolateral region of trunk, and web of ventral fin.  相似文献   

14.
The separation ofSclerotinia sclerotiorum (Lib.) de Bary, 5.trifoliorum Erikss., andS. minor Jagger into three distinct species has been based on traditional morphological and physiological criteria such as gross cultural characteristics, sclerotial size, ascus and ascospore dimensions, time of apothecial development in the field, and host association. However, these characteristics tend to be variable and some workers have concluded that the three fungi should be included in one species, 5.sclerotiorum. Recently, new data have been published on morphological, cultural, physiological, ontogenetic, enzyme pattern, mycelial interaction, and cytological characteristics of isolates ofSclerotinia spp. This information supplements, but does not replace, that available from more traditional taxonomic methods and helps to resolve the controversy on the taxonomy and nomenclature of these fungi. This article reviews the relevant literature on the biology of 5.sclerotiorum, S. trifoliorum, and 5.minor, with particular emphasis given to those differences between them that could be of significance regarding their specific nomenclature. After an introduction, mycelia, microconidia, sclerotia, apothecia, infection, control, and taxonomy and nomenclature are discussed. The authors conclude thatS. sclerotiorum, S. trifoliorum, andS. minor are distinct species. The characteristics used to distinguish between them are summarized in table form.  相似文献   

15.
Billie L. Turner 《Brittonia》1985,37(1):117-120
Two new species ofSenecio,S. sundbergii andS. neogibsonii, belonging to the sectionPalmatinervii are described, illustrated, and compared to their nearest relatives,S. aschenbornianus andS. lanicaulis.  相似文献   

16.
A new pomacentrid fish,Chromis okamurai, is described from a single specimen taken from the Okinawa Trough (25°53.4′N, 123°59.4′E), in 135–175 m. This species is most closely related to the deep-dwellingC. mirationis, sharing with it the same meristic data (in particular XIV dorsal spines and 2 upper and lower caudal spinules), large eye, and relatively deep body. It differs in having a small round posterior nostril (large and slit like inmirationis), longer second anal spine, shorter pelvic fins, and in color: two dark brown stripes on body and a pale pectoral-fin axil (mirationis has a single, midlateral, yellow to yellowish brown stripe which extends broadly onto lower part of caudal fin, and a black pectoral axil).  相似文献   

17.
Synopsis Unique to darters of the subgenusOdontopholis ofPercina andPercina (Imostoma)antesella is the development of a caudal keel in breeding males. The keel is a semicircular extension of the ventral surface of the caudal peduncle and anterior lower caudal fin. The reproductive behavior of species ofPercina implies an adaptive function related to the burial and fertilization of eggs. The caudal keel appears to serve as a plow-share which, in conjunction with an elongated anal fin, facilitates the transfer of sperm from the male's genital opening to eggs buried in the substrate by the female.  相似文献   

18.
19.
Five taxa ofSolanum sect.Basarthrum were studied in an effort to clarify their taxonomic position and to determine the effective evolutionary mechanisms. Methods included an analysis of chromosome number and behavior, artificial hybridizations and a study of herbarium material. The data suggest thatS. canense andS. suaveolens are closely related and that 5.suaveolens may have been the progenitor ofS. canense. The only successful interspecific cross involving one of these two species was vigorous but highly sterile. Evidence from both morphology and crossing studies indicates a close relationship betweenS. basendopogon andS. caripense. Hybrids between these two species with relatively high fertility through the F3 generation were secured. The status ofS. basendopogon f.obtusum remains a problem since there is but one collection of the typical form. The placement ofS. sanctae-marthae in sect.Basarthrum is considered problematic. Virtually none of 170 interspecific crosses with this species were successful. Seed size and the presence and size of a seed wing are proposed as useful morphological characters in sect.Basarthrum. There is apparently a correlation between short styles and self-compatibility. All species are diploid (n = 12) and no chromosomal or meiotic aberrations were noted in the species or hybrids. Most of the more than 1,000 interspecific crosses failed. Most of the hybrid fruits bore no seeds or seeds which did not germinate. The primary barriers separating species are considered to be strong prefertilization isolating mechanisms and ecogeographic factors.  相似文献   

20.
A molecular phylogeny of the familyIridaceae based on the plastid generps4 was obtained using both parsimony and distance methods. Thirty-four species were examined together with eight outgroup species. Results show that theIridaceae are monophyletic, and thatIsophysis is likely to be the earliest emerging genus. SubfamilyIxioideae plus the generaAristea andNivenia form a strongly supported clade. Within subfam.Iridoideae, the tribeIrideae includes the genusBobartia (of disputed position), and the tribeMariceae includesCypella. The division ofIridoideae into tribes is consistent with their geographical distribution.  相似文献   

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