摘要:

A comparison of the genital features ofArion urbiaeand A.anguloisuggests that the species are extremely similar, if not identical. This hypothesis is supported by an electrophoretic analysis of 13 putative enzynme loci, which shows that the two species are also genetically yery similar (I = 0.947), while the relatedA. subfuscusconsists of two distinct genetic types (I = 0.421). These results are further confirmed by a study of esterase profiles obtained with isoelectric focusing. It is therefore concluded thatA. urbiaeandA. anguloiare most probably conspecifie, whereas the genetic types ofA. subfuscusmay represent two different species.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1994.tb01467.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

A new species of polyclad flatworm,Pseudoceros imitatussp. nov.(Polycladida, Pseudocerotidae), is described from Papua New Guinea and recorded from the Great Barrier Reef, Australia. This polyclad resembles the phyllidiid nudibranchPhyllidiella pustulosa(Cuvier) (Nudibranchia, Phyllidiiae) in size and colour pattern. It is proposed thatP. imitatusis a mimic of the aposematic nudibranch in order to avoid predation by reef fish. Mimicry between polyclad flatworms and opisthobranch molluscs is reviewed.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1994.tb01468.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Species boundaries in the North AmericanDaphnia longispinagroup have proved difficult to establish on the basis of morphology alone. This confusion may be due to hydridization, phenotypic plasticity or the existence of sibling species. We therefore used genetic analysis to delineate species boundaries by examining 27 North American populations belonging to thelongispinacomplex for variation at 15–26 allozyme loci. The populations consisted ofDaphnia thoratafrom two western sites and two eastern sites,Daphnia galeata mendotaefrom its type location and seven sites across its range, andDaphnia roseafrom eight temperate and seven arctic sites. Two populations from the Eurasianlongispinacomplex were also included for reference. Populations assigned toD. galeata mendotaeformed a genetically cohesive group, whereas a genetic dichotomy was found between temperate and arcticD. rosea, suggesting that this taxon includes two species. Genetic analysis also confirmed the distinctness of westernD. thoratafrom other members of thelongispinagroup. Unexpectedly, eastern populations resemblingD. thoratawere genetically more similar to temperateD. roseathan to any helmeted species (D. galeata, Daphnia hyalinaorD. thorata). Our results suggest that the helmet character is a poor indicator of phylogenetic relationships, as the genetic ability to produce this feature has been lost or acquired several times in the evolution of thelongispinagrou

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1994.tb01469.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

New specimens from the Pacific coast of Panama provide the opportunity to redescribePyura lignosaMichaelsen, 1908. The status of this species and of three other similar pyurids (P. vannameinomen novum,P. cadamostoisp. nov., andP. shiinoiTokioka, 1949) is examined, and all four species are identified, described, and compared.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1994.tb01470.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Nine species of the cheilostomate bryozoan genusParasmittinaOsburn, 1952, are described. Neotype specimens are selected forP. parsevalii(Audouin) andP. raigii(Audouin).P. hastingsaeSoule and Soule,P. agathaesp. nov.,P. parsloeparsloeisp. nov.,P. pectinatasp. nov.andP. solenosmilioidessp. nov.are described from Australian localities.P. fistulata(Harmer) is redescribed andP. decorataSoule and Soule is placed in the synonymy ofP. delicatula(Busk).

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1994.tb01471.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The predatory behaviour of 31 species ofMyrmarachne, ant‐like salticids, was studied in the laboratory and the field. The ant‐like morphology and locomotion of these spiders appears to function primarily in Batesian mimicry. No evidence was found ofMyrmarachnefeeding on ants. However, predatory sequences were found to differ considerably from those typical of salticids. Instead of stalking and leaping on prey,Myrmarachnelunged at prey from close range.Myrmarachneused its legs I to tap prey before lunging, another unusual behaviour for a salticid.Myrmarachnefed on a wide range of arthropod prey in nature and the laboratory, but appears to be especially efficient at catching moths. Also,Myrmarachnetends to open up, or enter into, other spiders' nests and eat other spiders' eggs.Myrmarachnemales were less efficient than females, in laboratory tests, at catching various types of arthropod prey, but they appear to be as efficient as females at oophagy.Myrmarachnetend to use webs of other spiders as nest sites, but no evidence was found ofMyrmarachnepreying on spiders in webs. It appears that the unusual features ofMyrmarachne'spredatory and nesting behaviour are important in enabling these spiders to preserve their ant‐like appea

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1994.tb01472.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1994.tb01467a.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY