摘要:

The cuticle ofSquilla desmarestidoes not show a well‐defined Balken structure as described by Krishnakumaran (1956) inS. holoschista. Parallel fibres follow curved courses of differing orientation in the horizontal plane, and successive layers of fibres are separated by laminar membranes of different chemical composition from the remainder of the cuticl

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1978.tb01042.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

An attempt has been made to determine the absoulte age, in terms of incremental growth layers in the dentine of unworn incisors, of dugong skulls already relatively aged by Mitchell (1973). About 60 loose incisors were also included in the study. Layer numbers were found to range from zeros to 57 1/2. Upper jaw tooth succession was related to layer number, tooth 5 coming into wear at 2 1/2 to 3 layers and tooth 6 between 5 1/2 and 8 1/2 layers. The date of death of the animals from which 11 of the skulls came was known with certainty and a twelfth possibly, and this information indicated that the layers are either annual or biannual but are unlikely to be laid down more frequently than this. It is suggested that sexual maturity is reached at approximately 10 layers (i.e. 10 or 5 years of age).

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1978.tb01043.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Investigations were made on the length‐weight relationship and condition factor of Esomu danricus (Ham) from ponds and flowing water channels. These relationships could be represented by the regression equations, log W = ‐2.6252 + 3.2451 log L (for channel fishes) and log W = ‐1.5390 + 2.6318 log L (for pond fishes). The correlations were significantly high (P<0.001). The mean values of condition factors were 0.529 and 0.713 for pond and channel fishes, respectively. The additive action of various factors in stagnant ponds, such as oxygen deficiency, stratification of indispensahle nutrients at the bottom, accumulation of body wastes of fishes, and unoxidized chemical compounds, competition for many necessities of life as space, food, shelter, seemed to adversely affect the growth rate and condition factor of pond dwelling fishes. Contrary to this the circulation of water induced by currents in the channels appeared to cause mixing of water at all depths to even out differences in dissolved oxygen concentration, temperature, nutrients, besides minimizing the effect of repressive factor. Such conditions invariably offered more opportunities to fishes to conserve almost all the available space and other resources in the habitat. This ensured rapid growth as evidenced by higher condition factor of the flowing‐water fishes as compared to their counterparts occurring i

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1978.tb01045.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

A new aphid genus Raychaudhuriella and two new specices viz. Raychaudhuriella myzaphoides and Rhopalosiphoninus sensoriatus are described from Himachal Pradesh, north‐west Himalaya. The affinity of Raychaudhuriella gen. nov. is drawn with Aspidophorodon Verma, Cavariela del Guercio, Myazphis van der Goot, Tricaudatus Narzikulov and Vesiculaphis del Guercio. Figures and biometrical data of the new species have been provide

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1978.tb01046.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

The specimen labelled Taenia heterosoma Baird 1853, comprising fragments of a parasite from the intestines of a frigate bird identified as Tachypetes aquila (=Fregata aquila (L.)) and collected in Jamaica by Mr Gosse, was undescribed but considered by Baird to be synonymous with ‘Taenia Pelecani aquilae’ Rudolphi. The frigate bird Fregata aquila (L.) of Ascension Island was confused with that of the Caribbean Sea and its islands, which bird is now known as Fregata magnificens rothschildi Mathews, 1915. Taenia heterosoma, identified as a species of Tetrabothrium (=Tetrabothrius Rud.) by Monticelli (1891), was regarded as species inedita by Fuhrmann in 1899, then as nomen nudum in 1908, to be revived by him in 1913 and applied also to a parasite of Sula bassana (L.) (=Morus bassanus). The brief and first description, that by Fuhrmann in 1932, combines characters of the cestode from the frigate bird and characters of that from the gannet. He gives both frigate bird and gannet as hosts, though Baer (1954) ascribed the parasite to one host only, Morus bassanus. The name T. heterosoma Baird, 1853 is replaced by Tetrabothnus bairdi sp. nov. from Fregata magnificens rothschildi and T. bassani sp. nov. from Morus bassa

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1978.tb01047.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

A new subspeciesCephalophus ogilbyi crusalbum, of Ogilby's duiker, is described from Gabon. It is the only duiker with white legs and is isolated from previously described subspecies ofC. ogilbyi.

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1978.tb01048.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

A new small theropod dinosaur, documented by an incomplete skeleton and three frontals, is described from the Judith River Formation (Upper Cretaceous: Campanian) of south‐central Alberta.It is distinguished from bothStenonychosaurusandDromaeosaurusby the structure of the frontal and by the marginal dentition.It resemblesStenonychosaurusin the structure of the frontal and the Dromaeosauridae in the shape of the endocranial cavity and other skeletal features.The material is referred to a new genus and species of the Dromaeosaurida

ISSN:0024-4082    

DOI:10.1111/j.1096-3642.1978.tb01049.x

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY