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1.
2.
The nocturnal migratory activity of the six most abundant Gastrosaccinaeliving off the European coast, namely Gastrosaccus sanctus,Gastrosaccus spinifrr, Anchialina agilis, Haplostylus lobatus,Haplostylus lobatus var. armata and Haplostylus norrnani. wasstudied. Both Gastrosaccus perform horizontal and vertical migrationsnear sandy beaches. These migrations involve the whole population,which exhibits a superficial or hyponeustonic distribution inthe water column. Anchialina and Haplostylus perform verticalmigrations from inshore to slope waters. The timing of pelagicphases, as well as the distribution in the water column, dependon age. sex, depth and clarity. Male A.agilis and H.lobatusshow intense migratory activity leading to a hyponeustonic distributionin mid-shelf and slope waters a few hours after dusk. Femalesand juveniles show continuous pelagic phases and a uniform distributionfrom dusk to dawn. Haplosiylus lobatus var. armata and H.normanipopulations exhibit the same behaviour, consisting of overnightmigrations and a uniform to deep nocturnal distnbution. In shallowwaters, male Anchialina and Haplostylus no longer exhibit hyponeustonicbehaviour and their nocturnal distribution becomes more andmore deep as clarity increases. Above the slope, animals thatmigrate from the continental shelf during the night sometimesadopt permanent pelagic behaviour above more than 200 or 300m in depth. but upward nocturnal migration persists and leadsto superficial stratification, albeit delayed. Slow morningdescents to the bottom can occur even further from the 500 misobath.  相似文献   

3.
The larval stage of Tortopus is redescribed based on three species: T. puella from North America, the only species of the genus previously known from larva, and the larvae of T. obscuripennis and T. sarae from South America described here. Generic characters of the larva include: relatively large finger-like gill near base of maxilla, inner margin of mandibular tusks with a subdistal tubercle, straight or weakly convex frontal ridge present between antennae, reduced unilamellated gill on abdominal segment I. Additionally the male imagines of both Neotropical species are described for the first time, and T. obscuripennis is recorded from Bolivia. Diagnoses, SEM photographs, and illustrations are given for the new stages described and for the identification of the three Tortopus species known as larvae.  相似文献   

4.
Eodiaptomus phuphanensis n. sp. is described from two localities in the Phu Phan National Park, northeast Thailand. The new species is the eighth member of the genus Eodiaptomus and the third species recorded from Thailand. It belongs to the lumholtzi‐group, and is most closely related to E. sanoamuangae Reddy and Dumont , 1998. The third endopodite‐segment of P2‐P4 in both sexes of E. phuphanensis n. sp. bears seven setae as in E. sanoamuangae, instead of six as in the remaining species of the genus. Nevertheless, the new species can be distinguished from the other congeners by the distinct shape of the endopodite of the male right P5 and the absence of hairs on lateral margins of the female caudal rami.  相似文献   

5.
Sampling for mysid shrimps in shallow coastal waters of Mozambique provided new distribution records for Siriella brevicaudata Paulson, 1875, Gastrosaccus bispinosa Wooldridge, 1978, Gastrosaccus longifissura Wooldridge, 1978, Dioptromysis proxima Nouvel, 1964 and Anisomysis maris rubri Bãcescu, 1973. Rhopalophthalmus tropicalis sp. nov. and Gastrosaccus mozambicus sp. nov. are described for the first time. The former species is distinguished from its closest relative R. terranatalis O. Tattersall, 1957 by its much smaller size, the lack of serrations on the lateral spines of the telson, the structure and arrangement of the spines on the antennal sympod and the number of subdivisions of the propodus of the thoracic endopod. Adult males of G. mozambicus sp. nov. show affinity to G. bispinosa, but the two species are separated by the form of the two distal exopod segments on the 3rd pleopod.  相似文献   

6.
A new species of the genus Ranunculus, R. uttaranchalensis, is described from Gangotri National Park, Uttaranchal in Western Himalaya, India. It is distinguished from the closely allied R. lobatus in having radical leaves sub‐cordate with hairy lamina base and petiole hairy above; cauline leaves sessile, 3–7 lobed with linear to narrowly lanceolate lobes; sepals usually reddish brown, externally hairy; petals rounded‐obovate and oblong, receptacle glabrous except 1–3 hairs at the top.  相似文献   

7.
A new species of poecilostomatoid copepod, Hemicyclops tanakai n. sp. was collected from burrows of the mud shrimp Upogebia major in an estuarine mud-flat in Tokyo Bay. The new species can be distinguished from its congeners by combination of the following characteristics: setation of the antennule, the segmentation of the antennule, the length–width ratio of the caudal ramus, the ornamentation on the third segment of antenna and the shape of the genital double somite.  相似文献   

8.
Comparative investigations on the morphology, life-history, and reproduction of 3 cultivated strains of the atmophytic green algaApatococcus lobatus are presented. Some ultrastructural features are added to the results of earlier investigations, and comments on the systematics and ecology are given. Morphology and cytology of each strain is variable and shows considerable overlapping. The results support the view thatApatococcus consists of a single variable species (A. lobatus) only. For the epiphytic algal associationPleurococcetum vulgaris the more significant termApatococcetum lobati is proposed.
Herrn Prof. Dr.Lothar Geitler zu seinem 90. Geburtstag gewidmet.  相似文献   

9.
The green microalga Apatococcus lobatus is widely distributed in terrestrial habitats throughout many climatic zones. It dominates green biofilms on natural and artificial substrata in temperate latitudes and is regarded as a key genus of obligate terrestrial consortia. Until now, its isolation, cultivation and application as a terrestrial model organism has been hampered by slow growth rates and low growth capacities. A mixotrophic culturing approach clearly enhanced the accumulation of biomass, thereby permitting the future application of A. lobatus in different types of bio‐assays necessary for material and biofilm research. The ability of A. lobatus to grow mixotrophically is assumed as a competitive advantage in terrestrial habitats.  相似文献   

10.
Impacts of urban development on aquatic populations are often complex and difficult to ascertain, but population genetic analysis has allowed researchers to monitor and estimate gene flow in the context of existing and future hydroelectric projects. The Lower Mekong Basin is undergoing rapid hydroelectric development with around 50 completed and under-construction dams and 95 planned dams. The authors investigated the baseline genetic diversity of two exploited migratory fishes, the mud carp Henicorhynchus lobatus (five locations), and the rat-faced pangasiid catfish, Helicophagus leptorhynchus (two locations), in the Lower Mekong Basin using the genomic double digest restriction site-associated DNA (ddRAD) sequencing method. In both species, fish sampled upstream of Khone Falls were differentiated from those collected at other sites, and Ne estimates at the site above the falls were lower than those at other sites. This was the first study to utilize thousands of RAD-generated single nucleotide polymorphisms to indicate that the Mekong's Khone Falls are a potential barrier to gene flow for these two moderately migratory species. The recent completion of the Don Sahong dam across one of the only channels for migratory fishes through Khone Falls may further exacerbate signatures of isolation and continue to disrupt the migration patterns of regionally vital food fishes. In addition, H. lobatus populations downstream of Khone Falls, including the 3S Basin and Tonle Sap system, displayed robust connectivity. Potential obstruction of migration pathways between these river systems resulting from future dam construction may limit dispersal, which has led to elevated inbreeding rates and even local extirpation in other fragmented riverine species.  相似文献   

11.
The genus Amphictene is reported for the first time from Mexico. Previous records for America are restricted to Brazil (Amphictene catharinensis) (Grube, 1870), and Guatemala (Amphictene guatemalensis) (Nilsson, 1928). In this paper we describe a new species, Amphictene helenae sp. n., characterized by the presence of three pairs of tentacular cirri, while other species have only two pairs. The new species is closely similar to Amphictene catharinensis, and can be distinguished by the presence of a circular group of glandular papillae inserted between the lines of glandular cirri present from the second segment. Amphictene guatemalensis is redescribed based on type material; it differs from the new species in the presence of two pairs of tentacular cirri on segments 1 and 2, six pairs of glandular cirri on the third segment, and four glandular lobes fused in pairs on the fourth segment.  相似文献   

12.
This is the first report of a Stellicola in the Atlantic Ocean. Members of the genus had previously been found only in the Indo-Pacific. A new species, Stellicola hochbergi, is described and compared with S. caeruleus (Stebbing, 1900), S. femineus Humes & Ho, 1967, S. illgi Humes & Stock, 1973, and S. novaecaledoniae Humes, 1976. Stellicola hochbergi may be distinguished from its congeners by: a) endopod of leg 4 with formula of 0–1; II, 1; b) third segment of the exopod of leg 3 with formula of III,I,5; c) genital segment with two dorsal elevations; d) free segment of leg 5 more than 3:1; and e) genital segment much wider than long (135 × 220 µm).  相似文献   

13.
The first Japanese representative of the predominantly Nearctic genus Aplomerus Provancher, A. japonicus sp. nov., is described. This species can easily be distinguished from the other species by the black body. Morphologically this species resembles A. lineatulus (Say) from eastern North America but is separable by the sculpture of the propodeum and third metasomal tergite. The discovery of this species demonstrates a disjunctive distribution of the genus Aplomerus in East Asia and North America. Notes on habitat and adult behavior are also given.  相似文献   

14.
罗建  汪书丽 《西北植物学报》2012,32(8):1704-1705
描述了桔梗科蓝钟花属裂叶蓝钟花(Cyananthus lobatus Wall.ex Benth.)的一个新变型——白花裂叶蓝钟花(Cyananthus lobatus Wall.ex Benth.f.albiflorus J.Luo et S.L.Wang)。原变型的花冠为紫蓝色至淡蓝色,而新变型花冠为白色。  相似文献   

15.
Shimode  Shinji  Toda  Tatsuki  Kikuchi  Tomohiko 《Hydrobiologia》2000,432(1-3):127-131
A new Ryocalanoid copepod, Ryocalanus spinifrons, collected by the MTD net system at a depth of 1400 m from the southwestern part of Sagami Bay, Japan, is described. The new species is morphologically very close to R. infelix Tanaka, 1956 (female unknown) from the Izu region of Sagami Bay. It is distinguished from other species by the presence of 12 long spinules on the ventral inner side of the fifth pedigerous somite, nine setae on the coxal epipodite of the maxillule and nine large robust spinules on the coxal segment of the fourth leg. The row of five robust spines on the paragnath distinguishes R. spinifrons.  相似文献   

16.
Hae-Lip Suh 《Hydrobiologia》1993,259(3):187-193
Anthessius kimjensis n. sp. is described based on the specimens recovered from the pelecypod Solen grandis Dunker in the Korean coast of the Yellow Sea. The new species is distinguished from congeners by having a combination of characters: setal formula II, I, 5 on distal segment of leg 4 exopod, three terminal hooks on distal segment of second antenna, and ratio of length to width on caudal ramus (2.2:1).  相似文献   

17.
Six kinorhynchs were found in the stomachs of the Argentine red shrimp, Pleoticus mulleri (Bate, 1888) from the Argentine coast of Patagonia. Three new species are described: Condyloderes storchi n. sp., Pycnophyes argentinensis n. sp. and P. neuhausi n. sp. A fourth species, Kinorhynchus anomalus Lang, 1953 was previously known only from the coast of Chile. This is the third known record of kinorhynchs documented as a food source. Condyloderes storchi, n. sp. is the fourth new species in this genus. It is distinguished by its paradorsal cuspidate spines on segments 7 and 9, lateral accessory and ventrolateral spines on segments 3, 6, 7, 10 and 11. P. argentinensis, n. sp. has nearly equal sternal width for segments 3–11 (about 7% of the trunk length), episternal plates with three distinct areas along the anterior margin, mid-sternal plate with even margin, mid-dorsal spinose protrusions along the terminal borders of segments 11 and 12, and lateral terminal spines 176 μm long, about 21% of trunk length. P. neuhausi, n. sp.has a prominent posterior elongation of the tergal plate of segment 3, uneven lateral margins of the mid-sternal plate, a maximum sternal width at segment 3, no mid-dorsal spinose processes and mid-ventral thickenings on segments 10–12.  相似文献   

18.
The macrozooplankton and Benthic Boundary Layer (BBL) macrofauna over a coarse sand and pebble community in the Bay of Saint-Brieuc (western English Channel) were sampled with a WP2 zooplankton net and with a modified MACER-GIROQ suprabenthic sledge, respectively, from February 1994 to November 1995. One hundred and sixty-four species were collected in 44 suprabenthic sledge hauls and 19 taxa in 30 zooplankton net hauls. In the water column, appendicularians and cnidarians dominated, while, in the BBL, holoplanktonic amphipods, chaetognaths, amphipods and mysids dominated the fauna; among them Apherusa spp., Sagitta setosa Muller, Anchialina agilis (Sars), Sirella clausii Sars and Eusirus longipes Boeck were the dominant species. The density and biomass of the BBL macrozooplankton were lower than those of the macrozooplankton in the water column. The density and biomass of suprabenthos remained a low throughout the year. In the water column, density and biomass of macrozooplankton showed a maximum in spring and remained low from autumn to winter; conversely, in the BBL, the density and biomass of both macrozooplankton and suprabenthos were higher from summer to autumn. The change in abundance of both BBL and pelagic taxa was seasonal. Some species were primarily sampled in the water column (appendicularians, cladocerans and cnidarians), while others were preferentially found at the BBL (suprabenthic species, holoplanktonic amphipods and cephalopods). A third group was collected throughout the water column (chaetognaths and fish larvae).   相似文献   

19.
Three new lichomolgid copepods associated with the scleractinian Gardineroseris planulata (Dana) are described: Sociellus torus, n. gen., n. sp., characterized by a 2-segmented endopod in leg 3 and the lack of an inner seta on the first segment of the endopod in legs 1–3; Odontomolgus pumilus, n. sp., of very small size and having a much elongated free segment in leg 5 of the female; and Paramolgus ampullaceus, n. sp., distinguished by the bottle-shaped genital segment of the female. In addition, the harpacticoid Alteuthellopsis corallina Humes, 1981, is reported from this coral. With the inclusion of 3 species of the poecilostomatoid genus Xarifia already described (Humes, 1985) there are now 7 species of copepods known to be associated with Gardineroseris planulata on the Great Barrier Reef.  相似文献   

20.
A new species of cyclopoid copepod, Ochridacyclops nipponensis is described from Japan. This is the third species of the genus. The type material was collected from small streams in the mountainous regions in Shikoku. The new species can easily be distinguished from other members of genus by its 12-segmented antennule, by the proportional length of genital double-somite relative to the length of 3 free abdominal somites, and by the shape of caudal rami. The male is unknown.  相似文献   

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