861 research outputs found
Some morphological observations on the Neobradyidae Olofsson, 1917 (Copepoda, Harpacticoida) including the redescription of <i>Antarcticobradya tenuis</i> (Brady, 1910) comb. nov.
Neobrady pectinifera T. Scott, 1892 is thoroughly redescribed and figured. Parastenhelia (?) tenuis Brady, 1910 collected during the "Deutsche SĂĽdpolar Expedition 1901-1903" and placed species incerta sedis in the Parastenheliidae by Lang (1948) is also recognized as a Neobradyidae and assigned to a new genus Antarcticobradya gen. nov. The Neobradyidae are considered remnants of a formerly widespread group and brief reference is made to the phylogenetic relationship of the family
Crustacea Copepoda: <i>Amphicrossus pacificus</i> gen. et sp. nov., an erebonasterid copepod (Poecilostomatoida) from the New Caledonian continental shelf
A new species of Erebonasteridae, Amphicrossus pacificus, is decribed on the basis of a single female from a depth of 155 m north of New Caledonia in the Grand Passage zone. The new species is closely related to Erebonaster spinulosus Humes and for that reason the latter is transferred to the new genus Amphicrossus. Differences in body ornamentation and armature of maxilla, maxilliped and P4 serve to distinguish Amphicrossus and Erebonaster. Other noticeable discrepancies are found in the structure of the rostrum, the shape of the thoracic epimera and the design of the fifth pair of legs. A peculiar structure, the "sensory area", is shown on the posterior surface of enp-2 P2 in both Amphicrossus species which can be differentiated from each other on the basis of differences in antennulary setation, ornamentation of Pl-P4 (exopods, intercoxal sclerites) and length:width ratio of anal somite and PS exopod. The discovery of A. pacificus in the southern hemisphere considerably extends both the depth range and geographical range of the family
Superornatiremidae fam. nov. (Copepoda: Harpacticoida): An enigmatic family from North Atlantic anchihaline caves
A new family Superornatiremidae is described from 7 inland marine caves of Bermuda and from Jameos del Agua Cave, a sea water-flooded Holocene lava tube on Lanzarote in the Canary Islands. The family is proposed to accommodate three new genera, Superornatiremis, Neoechinophora and Intercrusia, and six new species: S. mysticus, N. fosshageni, N. daltonae, N. jaumei, N. karaytugi and I. problematica. The major diagnostic character is the unique leg 1 which exhibits supernumerary elements on the proximal and middle exopod segments and the middle and distal endopod segments. The increase of armature elements is regarded as a secondary phenomenon in copepod evolution and not as the result of character reversal. Other unique characters comprise the presence of an epicopulatory flap closing off the copulatory pore, the laterally displaced female gonopores and the paired copulatory ducts, the modified trilobate proximal endite of the maxilla, the fused labrum and labium (derived from the fused paragnaths) forming a well developed oral cone, the modified endopod of leg 2 and the transformation of the distal inner seta of P2-P3 enp-3 into a spine. The family is further characterized by the complete lack of sexual dimorphism on the swimming legs. The three genera can be differentiated primarily by the combination of P1 armature, structure of the outer exopod spines of P1, genital field morphology and segmentation of the male PS. The problematic status of Intercrusia is discussed. The new family is placed in the tisbidimorph complex of families and seems to occupy an intermediate position between the two free-living tisbid subfamilies Tisbinae and Idyanthinae. The biogeography of the family is briefly discussed
Anticipation of Tennis Shot Direction from Whole-body Movement: The role of movement amplitude and dynamics
International audienceWhile recent studies indicate that observers are able to use dynamic information to anticipate whole-body actions like tennis shots, it is less clear whether the action's amplitude may also allow for anticipation. We therefore examined the role of movement dynamics and amplitude for the anticipation of tennis shot direction. In a previous study, movement dynamics and amplitude were separated from the kinematics of tennis players' forehand groundstrokes. In the present study, these were manipulated and tennis shots were simulated. Three conditions were created in which shot direction differences were either preserved or removed: Dynamics-Present-Amplitude-Present (DA), Dynamics-Present-Amplitude-Absent (DA), and Dynamics-Absent-Amplitude-Present (DA). Nineteen low-skill and fifteen intermediate-skill tennis players watched the simulated shots and predicted shot direction from movements prior to ball-racket contact only. Percent of correctly predicted shots per condition was measured. On average, both groups' performance was superior when the dynamics were present (the DA and DA conditions) compared to when it was absent (the DA condition). However, the intermediate-skill players performed above chance independent of amplitude differences in shots (i.e., both the DA and DA conditions), whereas the low-skill group only performed above chance when amplitude differences were absent (the DA condition). These results suggest that the movement's dynamics but not their amplitude provides information from which tennis-shot direction can be anticipated. Furthermore, the successful extraction of dynamical information may be hampered by amplitude differences in a skill dependent manner
<i>Laophontopsis</i> Sars and the taxonomic concept of the Normanellinae (Copepoda: Harpacticoida): a revision
The taxonomic concept of the subfamily Normanellinae Lang (Harpacticoida, Laophontidae) is revised. As a result a new family Laophontopsidae is proposed to accommodate Laophontopsis Sars and two new genera Aculeopsis and Telodocus. It is concluded that the presumed boreo-mediterranean distribution pattern displayed by the type species L. lamellifera (Claus) is merely the result of erroneous identifications. The population of northwest Europe is assigned to a new species L. borealis and another new species L. monardi is proposed for Monard's (1928) material from Banyuls-sur-Mer. L. secundus Sewell is placed in the new genus Telodocus. Aculeopsis gen. nov. embraces only A. longisetosa spec. nov. and constitutes the most primitive genus of the family. The Laophontopsidae are placed within the superfamily Laophontoidea. The Normanellinae are provisionally upgraded to family level despite their diphyletic status because this narrows the diagnosis of the Laophontidae considerably. The genera are attributed to two clearly defined but non-related subfamilies, Normanellinae Lang (Normanella Brady) and Cletopsyllinae subfam. nov. (Cletopsyllus Willey, Pseudocletopsyllus Vervoort). The genus Pseudocleta Lang is relegated to incertae sedis within the Laophontoidae
Harpacticoida (Copepoda, Crustacea) van de Belgisch-Nederlandse kustzone en aangrenzende estuaria: stand van zaken en perspectieven
A new species of <i>Syrticola</i> Willems & Claeys, 1982 (Copepoda: Harpacticoida) from Japan with notes on the type species
A new species of Syrticola Willems & Claeys, 1982 (Harpacticoida: Cylindropsyllidae) is described from Okinawa, Japan. Morphological notes on the type species S. flandricus Willems & Claeys, 1982 and a key to the species are given. The inadequately described S. trispinosus A. Scott, 1896 is ranked as species inquirenda. The diagnosis of the genus is amended and its position in the Cylindropsyllidae re-assessed. Both sexes of S. intermedius sp. nov. were found to be infested by early parthenogenetic female stages of an as yet undescribed genus of Tantulocarida
Proposal of <i>Marbefia</i>, gen. n. and <i>Inermiphonte</i>, gen. n., including updated keys to the species of <i>Pseudonychocamptus</i> Lang, 1944 and <i>Paralaophonte</i> Lang, 1948 (Copepoda, Harpacticoida, Laophontidae)
Both sexes of the enigmatic laophontid species Pseudonychocamptus carthyi Hamond, 1968 (Copepoda, Harpacticoida) are redescribed in detail based on type and other material from Norfolk, England. The species exhibits marked differences with other Pseudonychocamptus species and is consequently fixed as the type of a new genus Marbefia, gen. n., being defined by the following autapomorphies: (1) P2–P4 enp-2 (except P4 enp-2 in ?) inflated, with two parallel rows of flimsy setular extensions; (2) P4 with sexually dimorphic setation on enp-2 (outer distal seta reduced in ?, very long in ?); and (3) antennule ? with spinules along posterior margins of segments 1–6. Laophonte danversae Hamond, 1969, “Laophontid male, ?gen., ?sp.” sensu Hamond (1969) [renamed as Inermiphonte hamondi, sp. n.] and Laophonte ?drachi Médioni & Soyer, 1966 are collectively placed in a new genus Inermiphonte, gen. n. which shares as sistergroup relationship with Harrietella T. Scott, 1906. Marbefia, gen. n. is considered sister to a clade comprising the genera Pseudonychocamptus Lang, 1944, Pilifera Noodt, 1952, Inermiphonte, gen. n. and Harrietella. Pseudonychocamptus kolarovi Apostolov, 2008 is transferred to Paralaophonte whereas Chislenko’s (1967) record of P. koreni Sars, 1908a is considered doubtful. Willey’s (1935) variety “fissirostris” of Paralaophonte brevirostris (Claus, 1863) is rejected pending a thorough analysis of the variability in the P. brevirostris complex of species. P. congenera mediterranea Lang, 1948 appears to be more closely related to P. lacerdai Jakobi, 1953 than to its nominotypical subspecies P. congenera congenera (Sars, 1908b) whereas P. pacifica galapagoensis Mielke, 1981 (here upgraded to full specific rank) is more similar to P. brevirostris than to its nominotypical subspecies P. pacifica pacifica Lang, 1965. A new species, Paralaophonte pallaresae, sp. n. is proposed for P. gracilipes Brady, 1910 sensu Pallares (1968). The potentially paraphyletic status of the genus Paralaophonte is discussed. Dichotomous identification keys are provided for the valid species of Pseudonychocamptus Lang, 1944 and Paralaophonte Lang, 1948
New family of deep-sea planktonic copepods, the Paralubbockiidae (Copepoda: Poecilostomatoida)
The deep-sea planktonic copepod Paralubbockia longipedia is redescribed from the type specimens, and a new family of Poecilostomatoida is proposed to accommodate it. The Paralubbockiidae fam. nov. is characterized by two unique plesiomorphies, the ventrally located fifth legs and the retention of a separate maxillulary palp, and by the apomorphic states of the endopods of the swimming legs and of the antenna. The sister group of the Paralubbockiidae is identified as the family Oncaeidae. These are the only two poecilostomatoid families that have retained a vestige of the geniculation mechanism in the antennules of the male. The genus Laitmatobius Humes is here regarded as incertae sedis within the lineage comprising the Oncaeidae and the Parulubbockiidae
Het meiobenthos van het Nederlands Continentaal Plat voorjaar 1991: rapportage in het kader van het Biologisch Monitoring Project
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