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1.
Ho  Ju-shey 《Hydrobiologia》1988,(1):555-560
Four species of Sunaristes (Canuellidae) are known to live in association with hermit crabs and exhibit a degree of host specificity. Although hermit crabs are common in many parts of the world, Sunaristes is notably absent from waters of the New World. The phylogeny of Sunaristes is here examined through a cladistic analysis. The reconstructed phologeny indicates that S. inaequalis and S. japonicus form a sister group, and its closest relative is S. tranteri. The sister taxon of this 3-species clade is S. paquri. It is assumed that Sunaristes evolved in the Paleocene on the north shore of the Tethys seaway. The constructed cladogram forms the basis for the analysis of vicariant events that led to the speciation and development of the present pattern of distribution of Sunaristes.  相似文献   

2.
Huys, R. & Iliffe, T. M. 1998. Novocriniidae, a new family of harpacticoid copepods from anchihaline caves in Belize.
A new family of fusiform, semi-planktonic harpacticoid copepods is described from two anchihaline caves, Caye Chapel Cave and Columbus Caye Blue Hole, on the Belize Barrier Reef. The Novocriniidae fam. n. is proposed to accommodate Novocrinia trifida gen. et sp. n. and is placed in the tisbidimorph complex of families (Tisboidea) by virtue of its maxilliped morphology. The new genus shares several characters with other tisbidimorph families but cannot be placed in any of them without an unnatural extension of their diagnoses. The Novocriniidae display a suite of plesiomorphic character states in most appendages from the antennules to the PS, indicating their basal position on the tisbidimorph phylogenetic tree. They exhibit a unique sexually dimorphic modification of the antennae, involving the transformation of two setal elements into filamentous sensory tufts. The unusual presence of supernumerary elements on the male PS baseoendopod is briefly discussed as well as the presence of a genuine but incipient oral cone derived from the labrum and medially fused paragnaths.  相似文献   

3.
Seasonal monitoring of the meiobenthos in the Dutch estuaries revealed an anomaly in density and diversity of harpacticoid copepods in the Westerschelde.Another Dutch estuary, the Eems Dollard, has comparable hydrodynamical, physical and sedimentological, characteristics and a similar fauna, but even in the severely organically polluted oligohaline mudflats of this estuary, annual average density and diversity of endo-epibenthic harpacticoid communities are higher than at similar less enriched meso- to polyhaline biotopes of the Westerschelde.Besides the concentrations of inorganic pollutants, such as phosphates and nitrates, the concentrations of pesticides, cyanide, detergents, phenoles, oils, polychlorobenzenes, polycyclic aromatic hydrocarbons and heavy metals were compared in both estuaries and compared to suggested permissive levels when available. From this it appears that these pollutants are present in the Westerschelde either in too low concentrations to be considered dangerous or at concentrations comparable to those occurring in the Eems Dollard, except for heavy metals.The load of a.o. Zn, Cu and Pb is distinctly and persistently higher in sediments and suspensions of the Westerschelde than in the Eems Dollard and copper is continuously present in a concentration at which, according to bioassays, egg production and larval development of planktonic copepods are severely affected. The remarkable scarcity of harpacticoid life on nutrient rich mudflats of the Westerschelde is thus probably due to heavy metal pollution.Since no other hardbodied meio- and macrobenthic taxa nor the plankton of this estuary show such a marked impoverishment, benthic harpacticoids prove to be suitable as indicators for the first stages of ecosystem-breakdown in estuarine and coastal zones polluted by trace-metals.  相似文献   

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5.
Two experiments were conducted in Tampa Bay, Florida, investigating the effect of harpacticoid copepod density in sediments on active water column dispersal. Both experiments involved adding harpacticoid copepods, in three density levels, to defaunated sediments and monitoring subsequent dispersal. The first experiment was conducted in the field in January 1985. Active dispersal in this experiment was judged density-dependent for total number of harpacticoids and the species or species groups Robertsonia spp. and Longipedia americana Wells. Dispersal of Zausodes arenicolus Wilson was density-independent. In the second experiment (July 1985), harpacticoids were brought into the laboratory. Dispersal in this experiment was density-dependent for total number of harpacticoids and a Nitocra spp. Dispersal of Robertsonia spp. was inversely density-dependent, while dispersal of Z. arenicolus and Metis holothuriae (Edwards) was density-independent. These results suggest density may influence the dispersal of some species of harpacticoid copepods.  相似文献   

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9.
Thistle  David  Eckman  James E. 《Hydrobiologia》1988,167(1):143-149
Given the quiescent physical environment and the low rates of bioturbation in the deep sea, biologically produced structures, such as animals tubes, may play an important role in creating habitat heterogeneity. In San Diego Trough, the cirratulid polychaete Tharyx luticastellus builds and inhabits a robust mud concretion (a mudball). Mudballs are abundant and persist after the worm has died or abandoned them. Our analysis of twelve 6.6-cm-diameter cores from 32° 51.02 N, 117° 46.97 W, taken with the submersible SEA CLIFF, indicate that one of 29 species of harpacticoids common in San Diego Trough is associated with Tharyx mudballs. This species (of the genus Heteropsyllus) responded only to mudballs containing worms, suggesting that any effects of the inanimate structure were not the cause of the association. We could detect no difference in bacterial numbers in sediments between control and occupied-mudball samples. This result suggests that the response does not result from gross differences in food levels near a mudball, but the possibility that there are differences in some preferred food cannot be discounted. An univestigated possibility is that Heteropsyllus responds to occupied mudballs because the worm's presence deters some (presumably small) predator.  相似文献   

10.
The metabolic responses to temperature changes and the reproductive strategies of four species of harpacticoid copepod are examined in relation to their depth distribution, susceptibility to predation and assumptions about food supply. Two species, one of which is heavily preyed upon, are confined to the surface layers and two species occur deeper in the sediment through most of the year. These latter species appear to have adopted different metabolic strategies in response to lowered food supply but both have a lower Q10 than surface dwelling species. In addition the surface species have the ability to regulate their respiratory demands at times of high, short-term, temperature fluctuations. Preliminary data suggests that generally, the surface species have shorter development times than those dwelling deeper in the sediment but until more information is available on the energetic costs of reproduction it cannot be shown that deeper dwelling species are more conservative in their reproductive strategies.  相似文献   

11.
Alexandercestus n. g. (Cestoda: Tetraphyllidea) is erected for two cestode species found parasitising the two known species of lemon sharks (Carcharhiniformes: Negaprion spp.). This new genus differs from all other phyllobothriid genera except for Hemipristicola Cutmore, Theiss, Bennett & Cribb, 2011, Marsupiobothrium Yamaguti, 1952, Nandocestus Reyda, 2008, Orectolobicestus Ruhnke, Caira & Carpenter 2006, Orygmatobothrium Diesing, 1863, Paraorygmatobothrium Ruhnke, 1994 and Phyllobothrium van Beneden, 1849 in possessing uniloculate bothridia with an apical sucker and neck scutes. Alexandercestus differs from Orectolobicestus and Nandocestus in lacking marginal loculi on the bothridia, from Paraorygmatobothrium in possessing uninterrupted vitelline follicles at the level of the ovary and from Phyllobothrium in being euapolytic as opposed to anapolytic and in lacking posteriorly bifid bothridia. The new genus lacks the central accessory bothridial organ seen in specimens of Orygmatobothrium, and lacks the central bothridial accessory sucker of specimens of Marsupiobothrium. Alexandercestus spp. compare most favourably with specimens of Hemipristicola, especially with respect to aspects of proglottid morphology, but differ in possessing aristate gladiate spinitriches rather than serrate gladiate spinitriches on the proximal bothridial surface. In addition, the bothridia of Alexandercestus spp. are comparatively more fleshy and foliose than those in specimens of Hemipristicola. Two new species of Alexandercestus n. g. are described, Alexandercestus gibsoni n. sp. from Negaprion acutidens, collected from off northern Australia and the Marshall Islands, and Alexandercestus manteri n. sp. from N. brevirostris, collected off the islands of Bimini and the Florida Keys. The two new species differ in total length and vitelline follicle distribution. Bayesian inference and parsimony analysis of the D1–D3 region of the large nuclear ribosomal DNA of 17 published and seven novel sequences placed A. gibsoni as the sister taxon to a clade containing Hemipristicola gunterae Cutmore, Theiss, Bennett & Cribb, 2011 and species of Paraorygmatobothrium. This result supports the erection of Alexandercestus as a genus separate from Hemipristicola and Paraorygmatobothrium. At the present time, species of Alexandercestus are known only from hosts of the carcharhinid genus Negaprion Whitley; examination of extensive survey data suggests this may be the extent of the host distribution of this genus.  相似文献   

12.
This paper contributes to a revision of the genus Halectinosoma . Four new species are described, based on examination of ectinosomatid material from localities in western Europe, eastern Canada and the Arctic. Halectinosoma mandibularis sp. nov. is distinguishable from other species by the reduced setation of the mouthparts and enlarged mandibular gnathobase. Halectinosoma latisetifera sp. nov. bears an affinity with H. cooperatum but is easily distinguished by the shape of the setae on the female fifth leg. A species previously erroneously ascribed to H. finmarchicum (Scott) by several authors is described here as Halectinosoma kliei sp. nov. Halectinosoma gothiceps (Giesbrecht) is redescribed and the closely related Halectinosoma paragothiceps sp. nov. is described and distinguished from H. gothiceps . It is considered likely that some previous records of H. gothiceps are in error.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 149 , 453–475.  相似文献   

13.
Two species of nudibranch molluscs are described from the northeastern Pacific Ocean on the west coast of North America. These are: a new aeolid species of Cuthona Alder & Hancock, 1855 (family Cuthonidae) from the Oregonian marine zoogeographical province and a new dorid species of Acanthodoris Gray, 1850 (family Onchidorididae) from the Panamic province in the Gulf of California. The internal anatomy and external features of each species are compared with related species. Differences in structure of the radula, reproductive system and other morphological aspects are described. A revision of the family Cuthonidae is included. Evidence is presented to include the genera Trinchesia Ihering, 1879, and Precuthona Odhner, 1929, within the genus Cuthona. Cuthona alpha Baba & Hamatani, 1963, is synonymized with Catriona columbiana (O'Donoghue, 1922). We consider the New World Cuthonidae to be composed of the following five genera: Catriona Winckworth, 1941; Cuthona Alder & Hancock, 1855; Embletonia Alder & Hancock, 1851; Tenellia Costa, 1877; and Tergipes Cuvier, 1805.  相似文献   

14.
Two new species of the genus Sporobolomyces and one of the genus Rhodotorula are described. Sporobolomyces elongatus and Rhodotorula armeniaca spp. nov. were isolated from the surfaces of leaves of Callistemon viminalis (Soland ex Gaertn.) G. Don ex Loud. and Sporobolomyces foliicola from the leaves of Banksia collina R. Br. growing at Armidale.  相似文献   

15.
The diversity of species assemblages which occupy a basal position in the trophic pyramid (typically unicellular algae in aquatic environments) is known to influence the interaction with organisms of higher trophic levels. A laboratory feeding experiment was conducted with cultures of three benthic diatom species (Navicula phyllepta, Grammatophora marina and Cylindrotheca closterium) as primary producers and three harpacticoid copepod species (Harpacticus obscurus, Paramphiascella fulvofasciata and Tigriopus brevicornis) as grazers to evaluate the effects of food diversity (and concomitant food availability) on grazing selectivity. This kind of selectivity experiments is singular for benthic harpacticoid copepods as so far, information on food selection of harpacticoids is scarce.Uptake of a unispecific food source by a single copepod species decreased as food diversity (and concomitant overall food concentration) increased. All three consumers reacted similarly to changing food diversity, but exhibited strong species-specific responses to food identity i.e. which diatom was added was crucial. Irrespective of level of food diversity, H. obscurus took up high amounts of G. marina, whereas both P. fulvofasciata and T. brevicornis preferred C. closterium when given the choice between different diatoms. As for zooplanktonic taxa, this experiment showed that in lower benthic marine food webs both prey organisms (primary producers) and grazers play a very specific role. Diversity of food and its identity are of critical importance at the base of the trophic pyramid, influencing trophic transfer from primary producers over grazers to higher trophic levels.  相似文献   

16.
Twenty-five species of parasitic copepods are presented, collected on fishes living in the Montenegro sea coasts. Among these species, belonging to ten families and sixteen different genera, fifteen are new records for the Adriatic Sea.  相似文献   

17.
With the discovery of Alteuthoides kootare gen. et sp. no v. , found living inside an hexactinellid sponge from offshore waters of New Zealand, and the synonymization herein of Paralteutha T. Scott with Eupelte Claus, the number of genera in the harpacticoid copepod family Peltidiidae Sars now stands at eight. In the morphology of the maxillipeds and the armature of the first leg exopods, Alteuthoides is most similar to Alteuthella (A. Scott) and Alteuthellopsis Lang. These shared apomorphies are regarded as convergent ecological specializations to a lifestyle as close associates of other marine invertebrates. Results of a cladistic analysis further assist in the interpretation of relationships within the family. Lang's speculation that Peltidium and Parapeltidium form an independent lineage from the ancestral peltidiid gains further support. Alteutha remains as the basal group to the second lineage in comparison with which all remaining genera are derived in some respect. Alteuthellopsis would appear to be the most advanced genus in the family. Because of recent additions to Neopeltopsis Hicks and Alteuthellopsis , revised diagnoses, together with a revised key to genera, are also presented.  相似文献   

18.
1. The value of algal fatty acids (FA) as diet biomarkers for benthic harpacticoid copepods was investigated. A high proportion of 18:1ω9 and 18:2ω6 FA was observed in the lipid reserve fraction of copepods fed with cyanobacteria. In contrast, a high proportion of 16:1ω7 and ω3 FA (including eicosapentaenoic) was present in the lipid reserve fraction of copepods grown on diatoms. 2. Copepods that were grown on cyanobacteria showed reduced survival and took 26% more time to develop from the first copepodid stage to adult than copepods that were grown on diatoms. Copepods feeding on the cyanobacteria showed reduced FA content when compared with animals fed with diatoms. This reduction in FA content was more pronounced in the apolar lipid fraction (mainly reserve lipids) than in the polar (mainly structural) lipid fraction. 3. The FA profiles of algae were used to calculate a function discriminating between diatoms and cyanobacteria. This function was applied to the FA profiles in the reserve lipid fraction of copepods and correctly classified copepod diet. 16:1ω7, 18:2ω6 and 20:5ω3 were the most important FA in the discriminant function. The suitability of this chemometric method to infer copepod diet was further tested by using algal class FA data from literature to derive the discriminant functions. The correct classification of the diet when the functions were applied to FA composition of the copepod reserve lipids suggests that this method may be employed in trophic web studies. 18:3ω3, 18:1ω9 and 16:1ω7 were the most important FA in the functions discriminating diatoms, cyanobacteria and green algae. The identification and quantification of the whole suit of 16:1ω7, 18:1ω9, 18:2ω6, 18:3ω3 and 20:5ω3 in trophic web studies is therefore of paramount importance to infer diet origin of aquatic herbivores. 4. The FA profile of copepod polar lipids did not reflect that of the diet. The presence of long chain polyunsaturated FAs in the polar lipid fraction of copepods feeding on the cyanobacterium suggests that C18 FAs from the diet may be elongated and desaturated by the copepod. The ability to elongate and desaturated FAs may reduce the importance of some FAs as diet biomarkers while it may turn the copepods into valuable trophic intermediaries in transferring organic matter from microorganisms to higher trophic levels.  相似文献   

19.
Halling RE  Baroni TJ  Binder M 《Mycologia》2007,99(2):310-316
Bothia is described as a new genus in the Boletaceae based on Boletinus castanellus described by C.H. Peck from eastern North America. A widespread, occasionally encountered taxon, Bothia castanella possesses a combination of macro- and microscopic features that has prompted past placement in seven different genera. Yet, as a species it is readily recognizable with its chestnut brown, dry pileus, decurrent, pale brown hymenophore with radially elongated tubes, a short, sometimes eccentric, exannulate stipe, yellow brown spore deposit and constant association with Quercus. Phylogenetic analyses of large subunit rDNA and BLAST searches using the ITS region confirm the placement of B. castanella as a unique generic lineage in the Boletaceae.  相似文献   

20.
广西植物二新种和一个新记录属   总被引:1,自引:0,他引:1  
唐赛春  李光照   《广西植物》1999,19(4):341-343
报道了在进行华南生物多样性调查过程中, 在广西发现的2 个广西植物新种和1 个新记录属。  相似文献   

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