摘要:

The neotropical freshwater family Potamotrygonidae appears to be the only stingray group that has radiated in a non‐marine environment. To assess the affinities of potamotrygonids to other rays, a phylogenetic analysis was undertaken using 39 morphological characters from 18 stingray groups. The single tree produced (CI = 0.80, RI = 0.88) suggests that neotropical freshwater rays are a monophyletic group, and that within Potamotrygonidae,Paratrygonis basal to a clade composed ofPlesiotrygonandPotamotrygon.The sister group to potamotrygonids was determined to be amphi‐AmericanHimantura—these taxa share synapomorphies of the ventral mandibular musculature and the hyomandibular/mandibular articulation. The topology suggests that potamotrygonids are derived from a freshwater‐invading ancestor that was distributed along the northern coast of South America (Pacific and Caribbean) prior to the emergence of the isthmus of Panama. This hypothesis conflicts with parasite‐based biogeographic scenarios of a stricdy Pacific origin for potamotrygonids. General systematic results concerning urolophids, dasyatids, and pelagic myliobatoid stingrays are also

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1996.tb02189.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Relationships between patterns of geographic variation in cranial morphology and selected abiotic variables were studied in the puma (Puma concolorLinnaeus). Our dataset consisted of 11 cranial, 6 dental, and 2 mandibular measurements of 1700 adults, which were separated by gender and age class and analysed by univariate and multivariate statistical procedures. Variation in size was correlated with precipitation, but size was more highly correlated with latitude and temperature. The pattern of geographic variation in size ofP. concoloris consistent with Bergmann's rule; populations with larger pumas occur more distant from the equator than populations with smaller pumas. A combination of climatic and biotic factors contribute to patterns of geographic variation in size ofP. concolorin North and South America.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1996.tb02190.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Troglocyclopina balearicagen nov. ap. nov.andMuceddina multispinosagen nov. sp. nov.are described from the flooded coastal karst of the Balearic Islands, and from caves on Sardinia, the Balearics, and Lanzarote (Canaries), respectively. Both taxa seem to prefer anchihaline habitats with water salinities in excess of 18%, althoughTroglocyclopinahas also been found in more reduced salinity cave lakes located some distance from the coast. These new taxa are the first cyclopinids to be reported from caves, all previous citations of cyclopinids from hypogean environments relate only to the marine interstitial. The small clutch‐size exhibited byTroglocyclopina balearica(two eggs per sac) and the absence of the exopodal seta on the antennaat Muceddina multispinosaare interpreted as troglomorphic features, in addition to the absence of the nauplius eye and the lack of body pigmentation in both taxa. The derivation of both taxa from shallow‐water, hyperbenthic marine ancestors is propo

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1996.tb02191.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Sperm transfer by spermatophore is reported as a common and possibly primitive feature of the Diopsidae (Diptera, Schizophora). Spermatophores occur in four out of five investigated genera, inCyrtodiopsis, Diasemopsis, Teleopsis, and inSphyracephala, which is positioned close to the base of the family. Within the genusDiopsisthe spermatophore is subject to reduction. Spermatophore size and copulation duration are positively correlated across the species. This is only partially explained by the time requirement of sperm transfer. Parsimony in time and material seems to be favoured in species with high mating frequency at special aggregation sites, whereas high investment in time and material occurs in species that do not mate preferentially at certain times or locations. The utilization of spermatophores has strong implications on the possibilities of sperm competition and cryptic female choice and may account for the occurrence of a postcopulatory passive phase or prolonged mating in some species. The increasing number of records of spermatophores in Diptera is reviewed.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1996.tb02192.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Book reviewed in this article:Badgersby Ernest Neal and Chris Cheeseman. T&A D Poyser Natural History Ltd.The Lost Birds of Paradise, by Errol Fuller.Leks, by Jacob Högland and Rauno V. Alatalo. Monographs in Behaviour and Ecology

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1996.tb02193.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY