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1.
The statocysts of Cranchiidae are unlike those of all other squids. They are very varied: at one extreme is Bathothauma with a very large sac unique in having no internal interruptions. Conversely Egea has more of these anticristae than any other cephalopod. They are arranged in patterns that are different from those of other squids and they are sometimes very long and thin. The anticristae are large and numerous in the cranchiids that are perhaps more rapid swimmers and more active in hunting their prey, for example Mesonychoteuthis, Megalocranchia, Egea or Taonius. However, in the moderately large cranchiids Teuthowenia and Galiteuthis the statocyst cavities are little interruped by anticristae.
The conditions of the statocysts are found to correspond well with the cladistic analyses of relationship within the family performed by N.A. and R.S. Voss, except for those of Teuthowenia and Galiteuthis which stand apart, having relatively uninterrupted cavities. Other genera showing this condition are mostly small animals and form a group of presumably neotenous forms as suggested by N. Voss. It is discussed whether these may be the more primitive genera in the group. Possibly the Cranchiidae arose as neotenous buoyant squids with a peculiar mantle cavity and coelom and uninterrupted statocysts. Later genera exploited these characters and when they became more active swimmers they developed anticristae with an original pattern, allowing monitoring of more rapid turns.  相似文献   

2.
On 16 June 1979, a herd of 41 sperm whales stranded near the mouth of the Siuslaw River in Florence, Oregon. The stomach contents from 32 whales were collected, identified to the lowest taxonomic level possible, enumerated, and measured. A total of 20,247 cephalopod lower beaks that represented 24 species from 14 different families were recovered. The most numerous species were Histioteuthis hoylei (25.9%), Taonius borealis (12.9%), Galiteuthis phyllura (11.2%), Gonatopsis/Berryteuthis type (10.9%), and Moroteuthis robusta (10.7%). Reconstructed estimates of mass indicated that M. robusta contributed almost 50% of the total mass of cephalopods consumed, followed by H. hoylei (19.3%), and T. borealis (7.0%). The most important species in the diet of stranded whales were M. robusta, H. hoylei, T. borealis, G. phyllura, Octopoteuthis deletron, and Gonatopsis/Berryteuthis type. There were significant differences in the diet of males and females, but no differences between sperm whales of different age groups. Overall, sperm whales primarily consumed small cephalopods that were likely eaten south of 45ºN in or near the California Current System. This study provides new estimates of the food habits of sperm whales in the northeast Pacific from one of the largest strandings of this species.  相似文献   

3.
A comparative study was carried out of the substrate and inhibitory specificity of cholinesterase preparations from squids, representatives of 3 genes and 5 species of the Gonatidae family:Berryteuthis (B. magister andB. anonichos),Gonatus (G. kamtschaticus andG. tinro), andGonatipsis (G. borealis), that have overlapping habitation areals in the Bering Sea. As substrates, there were used bromides of acetylthiocholine, propionylthiocholine, and butyrylthiocholine, as organophosphorus inhibitors, diisopropylfluorophosphate, a cation-containing inhibitor, and 4 hydrophobic compounds. The homogeneity of the cholinesterase activity in these preparations has been shown, the intergenus and interspecies differences in the enzyme properties are revealed, and also the peculiarity of properties of enzymes from Gonatidae squids is emphasized in comparison with cholinesterase from the Pacific squidTodarodes paciflcus and “standard” mammalian enzymes (from human erythrocytes and horse blood serum). The revealed interspecies differences are discussed in terms of evolutionary development of the Gonatidae family.  相似文献   

4.
Statolith morphology and microstructure were studied in twocommon species of panktonic cranchiid squids, Belonella borealis[four juveniles with mantle length (ML) 375–450 mm] andGaliteuthis phyllura (13 paralarvae and juveniles, ML 9–235mm),caught near the bottom and in pelagic layers over the continentalslope of Siberia in the northwest Bering Sea. The total numberof growth increments within the statoliths ranged from 277 to294 in B.borealis and from 10 to 209 in G.phyllura. Assumingthat these increments were produced daily, both species growrapidly in length (daily growth rate = 1.13mm day–1 duringthe first 8–10 months of their juvenile phase in the mesopelagiclayers, prior to migration into deeper waters for maturation.  相似文献   

5.
Paralarvae of the family Gonatidae were sampled in the Gulfof Alaska during spring 2001–2003. Taxonomic characterswere determined to allow identification of the specimens tospecies. The dorsal head chromatophore pattern (DHCP) was themost robust character and allowed identification to speciesfor the first time without requiring the removal and examinationof the radula. Six different DHCPs were found among the sixspecies in the study area. The 1140 specimens collected consistedof the following six species: Berryteuthis anonychus (759),Berryteuthis magister (71), Gonatopsis borealis (155), Gonatuskamtschaticus (1), Gonatus madokai (4) and Gonatus onyx (143).The specimens had a size range of 3.0–20.63 mm dorsalmantle length with the majority of specimens smaller than 10 mm.All species showed an increasing trend in abundance from theshelf (0–200 m) to the slope (200–1000 m)to the basin (>1000 m) except G. onyx in 2001 and 2002.Wide variation in distribution and abundance was found for thefour most abundant species; however, in general, B. anonychuswas most abundant and widely distributed, followed by Gonatopisborealis, Gonatus onyx and B. magister. (Received 28 April 2006; accepted 1 February 2007)  相似文献   

6.
A taxonomic revision of Tectaria from New Caledonia is presented here based on a thorough study of herbarium specimens from New Caledonia and adjacent Pacific islands. Six species of Tectaria are presently recognized in New Caledonia. Tectaria kouniensis and T. pseudosinuata are reduced to synonyms of T. dissecta and T. sinuata, respectively. The morphological limit between T. seemannii and T. sinuata and the confused specimen citations in previous accounts are clarified. Apart from T. dissecta, the other five species, i.e. T. lifuensis, T. moorei, T. seemannii, T. sinuata and T. vieillardii, are mainly distributed in New Caledonia, with only T. seemannii and T. sinuata recently reported also from Vanuatu. A key to species, typification of accepted names and relevant synonyms, and brief comments on the relationships of species are provided.  相似文献   

7.
The paper `A taxonomic revision of the genus Taenia Linnaeus, 1758 s. str.' (Verster, 1969) gives concise characterisations, together with drawings of rostellar hooks and the terminal genital organs, of the 32 Taenia species and three subspecies which this author found to be valid. Yet, it is hardly possible to quickly identify a questionable species or to readily access information on their hosts, geographical range and synonyms. The present paper compiles these data and additional information on larval characteristics into tables. Measurements and numbers of hooks are shown using a graph. Additional data are included from authors not mentioned by Verster and for seven new species (T. dinniki, T. jaipurensis, T. kotlani, T. madoquae, T. saigoni and T. simbae), two re-validated species (T. krepkogorski, T. retracta) and two subspecies (T. polyacantha arctica and T. saginata asiatica) described since 1969. Reasons for rejecting one new species and one new subspecies are given. A table of definitive hosts and the Taenia species occurring in them is also included, as is one of synonyms from 1850 onwards. A good procedure for the staining and mounting of cestodes is described.  相似文献   

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The genus Genarchella Travassos, Artigas & Pereira, 1928 is reinstated for some species from South American fishes previously attributed to Halipegus Looss, 1899. Aspects of the morphology of G. genarchella Travassos, Artigas & Pereira, 1928 and G. parva Travassos, Artigas & Pereira, 1928 are redescribed. Astyanax bimaculatus, Moenkhausia doceana, Oligosarcus robustus and Salminus maxillosus are recorded as new hosts of G. parva, and H. cryptorchis Mané-Garzon & Gascón, 1973 and H. szidati Yamaguti, 1971 [= G. tropica of Szidat (1954)] are listed amongst new synonyms of this species. Aspects of the morphology of Thometrema magnifica (Szidat, 1954) and T. overstreeti (Brooks, Mayes & Thorson, 1979) are redescribed. T. rioplatense Lunaschi, 1989 is considered a synonym of T. overstreeti. New host-records of T. overstreeti are Pimelodus maculatus and Rhamdia sp. G. genarchella of Hamann (1986) is considered as synonym of T. overstreeti. Paravitellotrema Watson, 1976, Caballeroiella Lamothe-Argumedo, 1977 and Quadripaludus Jimenez, Guajardo & Briseno, 1981 are considered synonyms of Genarchella. The features distinguishing Halipegus, Genarchella and Thometrema Amato, 1968 are discussed.  相似文献   

10.
Geodia species north of 60°N in the Atlantic appeared in the literature for the first time when Bowerbank described Geodia barretti and G. macandrewii in 1858 from western Norway. Since then, a number of species have been based on material from various parts of the region: G. simplex, Isops phlegraei, I. pallida, I. sphaeroides, Synops pyriformis, G. parva, G. normani, G. atlantica, Sidonops mesotriaena (now called G. hentscheli), and G. simplicissima. In addition to these 12 nominal species, four species described from elsewhere are claimed to have been identified in material from the northeast Atlantic, namely G. nodastrella and G. cydonium (and its synonyms Cydonium muelleri and Geodia gigas). In this paper, we revise the boreo‐arctic Geodia species using morphological, molecular, and biogeographical data. We notably compare northwest and northeast Atlantic specimens. Biological data (reproduction, biochemistry, microbiology, epibionts) for each species are also reviewed. Our results show that there are six valid species of boreo‐arctic Atlantic Geodia while other names are synonyms or mis‐identifications. Geodia barretti, G. atlantica, G. macandrewii, and G. hentscheli are well established and widely distributed. The same goes for Geodia phlegraei, but this species shows a striking geographical and bathymetric variation, which led us to recognize two species, G. phlegraei and G. parva (here resurrected). Some Geodia are arctic species (G. hentscheli, G. parva), while others are typically boreal (G. atlantica, G. barretti, G. phlegraei, G. macandrewii). No morphological differences were found between specimens from the northeast and northwest Atlantic, except for G. parva. The Folmer cytochrome oxidase subunit I (COI) fragment is unique for every species and invariable over their whole distribution range, except for G. barretti which had two haplotypes. 18S is unique for four species but cannot discriminate G. phlegraei and G. parva. Two keys to the boreo‐arctic Geodia are included, one based on external morphology, the other based on spicule morphology. © 2013 The Linnean Society of London  相似文献   

11.
12.
Hae-Lip Suh 《Hydrobiologia》1996,330(3):231-244
The morphology of the gastric mill of 11 species in the family Euphausiidae is described. Two distinct arrangements can be recognized with respect to presence or absence of lateral teeth. One is the well-developed gastric mill of Thsanoessa gregaria, T. inermis, T. macrura and Pseudeuphausia sinica; the other is the gastric mill without lateral teeth of Nematoscelis atlantica, N. difficilis, N. megalops, Nematobrachion flexipes, N. sexspinosum, Stylocheiron abbreviatum, and S. carinatum. This supports the close relationships of the four species of both genera, Thysanoessa and Pseudeuphausia on the one hand and seven species belonging to Nematobrachion, Nematoscelis, and Stylocheiron on the other hand. The hypothesis that species in the same genus have similar gastric mill morphology, which was once rejected in the genus Thysanopoda, is accepted in all five genera examined here. Functional morphology of euphausiid foreguts is discussed.  相似文献   

13.
Inter-annual variation in the diet of female southern rockhopper penguins (Eudyptes chrysocome chrysocome) at Staten Island was studied during the early chick-rearing period to investigate the components of the diet and highlight some points of the possible food web in the study area. Gregarious crustaceans, small juveniles of squid and octopus, fish larvae and juvenile fish dominated the diet. There was a high degree of variability in the relative contribution of the different prey taxa during the three seasons studied. Overall, crustaceans were by far the most abundant in terms of number. Cephalopods contributed less to numbers, while fish was the least represented of the prey item in 2 years. Inter-annual variation in the proportion of prey items consumed was apparent only for some prey species: Thysanoessa gregaria, Gonatus antarcticus, Themisto gaudichaudii, Harpagifer bispinis and Salilota australis. These data suggest variability in the prey resources at sea during the study period and a subsequent opportunism of this penguin species to exploit what is differentially available. In terms of the food web in the area, we suggest an apparent relationship in the availability between T. gaudichaudii and G. antarcticus, and between T. gaudichaudii and H bispinnis. These relationships emphasise the importance of understanding food web interactions, especially those involving multiple trophic levels, when determining the role of upper-trophic level predators in marine systems.  相似文献   

14.
Two new species of the genus Telephata Meyrick which has been known to be monotypic, T. melanista, sp. nov. and T. ferruginula, sp. nov., are described from Papua New Guinea. A known species from the island, Lecithocera nitens Daikonoff, is transferred to this genus; Telephata nitens (Diakonoff), comb. nov. Keys to the species of Telephata, based on external and genital characters are given, along with illustrations of adults, wing venations, and male genitalia.  相似文献   

15.
菱科(Trapaceae)仅菱属(Trapa L.)1属,该属是典型的水生多型植物,中国乃至全球以往的分类处理分歧很大。基于文献查阅、野外采集、标本鉴定和栽培观察,对菱属植物分类的主要形态性状作了系统评价。果体大小和果冠变异稳定,可以用于属内种的划分,果喙大小和角的数目则可以用于种下变种的划分。在此基础上,对中国菱属作了分类处理,承认了细果野菱(T. incisa)和欧菱(T. natans)2个种,并将欧菱划分为6个变种,对其中4个变种作了新的组合。将10个种名和12个变种名处理为异名,并对5个名称(Trapa amurensis,T. bispinosa,T. dimorphocarpa,T. japonica,T. manchurica)作了后选模式标定。  相似文献   

16.
Deep-sea cephalopods are still poorly studied worldwide. In the case of the Mexican Pacific there is a general lack of basic information concerning their distribution and biology. A series of 132 specimens of pelagic and benthic deep-water cephalopods was obtained during the TALUD project. Samples were mostly obtained with benthic sampling gear that operated as mid-water trawls during the ascent of the nets. Micronekton and Isaacs-Kidd samplers were also occasionally used. The specimens (77 lots in total) were obtained at localities off western Mexico at depths between 122 m and 2200 m and belong to 31 species. Considering material identified to species level only, a total of 13 species were found only at a single station, while five others occurred in 5–6 stations (i.e., Leachia dislocata, Abraliopsis [Pfefferiteuthis] falco, Pterygioteuthis giardi, P. holeyi and Benthoctopus robustus). The most widespread species was Japetella diaphana, collected in 11 stations. Twenty-two of the 31 species are strictly pelagic, eight strictly benthic and one is benthopelagic. Significant new distribution records were obtained for seven species: Doryteuthis opalescens, Gonatus berryi, Todarodes pacificus, Opistoteuthis californiana, Benthoctopus leioderma, B. robustus and Graneledone boreopacifica.  相似文献   

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20.
The new genusTaniaEgea, Torrente & Sipman (Arthoniales) withT. lanosaas type species is described from Malaysia.Sagenidiopsisformerly treated as a genus of incertae sedis is included in the order Arthoniales, and the new combinationSagenidiopsis undulatum(Fée) Egea, Tehler, Torrente & Sipman is made. A key to the genera with byssoid thalli in the order Arthoniales is given.  相似文献   

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