Influence of Water Speed on Tadpoles of Ranidella signifera and R. riparia (Anura:Leptodactylidae)

1980 ◽  
Vol 28 (1) ◽  
pp. 79 ◽  
Author(s):  
FJ Odendaal ◽  
CM Bull
Keyword(s):  
Water Flow ◽  
South Australia ◽  
Breeding Habitat ◽  
Water Current ◽  
Similar Species ◽  
Flinders Ranges ◽  
Species Overlap ◽  
Influence Of Water ◽  
The Difference ◽  
Water Speed

Ranidella riparia is restricted to the Flinders Ranges of South Australia. and has a distribution largely allopatric to that of the morphologically similar species, R. signifera. The distributions of these two species overlap in the lower Flinders Ranges. In an experimental water flow, tadpoles of R. riparia were less often moved by the water current than those of R. signifera, and the difference increased with increasing water speed. In the Flinders Ranges most of the breeding habitat for frogs is in fast flowing creeks. The likelihood that tadpoles of R. signifera would be swept away in these creeks may be a factor restricting its distribution in this area.

The Influence of water flow rate on Pumping Rate in Mytilus Edulis using a Refined Direct Measurement Apparatus

1976 ◽  
Vol 56 (2) ◽  
pp. 311-319 ◽  
Author(s):  
D. I. Hildreth
Keyword(s):  
Water Flow ◽  
Direct Measurement ◽  
Water Flow Rate ◽  
Mantle Cavity ◽  
Water Current ◽  
Ciliary Activity ◽  
Pumping Rate ◽  
Influence Of Water ◽  
Food Particles ◽  
Flow Through

INTRODUCTIONWork on pumping and filtration rates of bivalve molluscs was initially concerned with the physiological concept of pumping water through the mantle cavity. Comprehensive reviews are given by Winter (1970) and Ali (1971). The methods are of two kinds; direct, in which the flow of exhaled water itself is measured, and indirect, in which the rate of clearance of food particles is used to calculate water flow through the gills.There is a disadvantage in the indirect method when used to calculate volumes of water pumped because it involves the assumption that a fixed percentage (often 100% with large particles) of the particulate matter passing through the gill system is retained. Pumping rate is thus estimated as a function of the particle collecting properties of the latero-frontal cirri, whereas the water current is produced by the lateral cilia. Although the structure of the latero-frontal cirri is now well documented (Moore, 1971), their efficiency in particle retention can alter under certain conditions (Dral, 1967). There is need, therefore, for direct measurement of the quantity of water pumped. Recent advances in the understanding of branchial innervation and the control of lateral ciliary activity also reinforce this point (Aiello, 1960, 1962, 1970; Paparo, 1972, 1973).The constant level chamber for direct measurement of pumping rate was devised by Galtsoff (1926), to ensure that separation of the exhalant water current from the bivalve was not interfered with by pressure differences produced by the process of separation. The apparatus has been used in various forms by Galtsoff (1926, 1928, 1946), Nelson (1935, 1936), Collier & Ray (1948), Loosanoff & Engle (1947), Loosanoff & Nomejko (1946) and more recently by Drinnan (1964) and Davids (1964).

The Behaviour of Barnacle Cyprids in Relation to Water Movement over a Surface

1955 ◽  
Vol 32 (3) ◽  
pp. 569-590 ◽  
Author(s):  
D. J. CRISP
Keyword(s):  
Water Flow ◽  
Velocity Gradient ◽  
Water Movement ◽  
Solid Particles ◽  
Water Current ◽  
Solid Boundary ◽  
Velocity Gradients ◽  
Solid Objects ◽  
Influence Of Water ◽  
Glass Tubes

1. The velocity gradient of the fluid close to the solid boundary is the most appropriate description of the conditions of water flow which affect the attachment of the larvae of sessile forms to solid objects. The nominal speed of the water movement past the object is of importance only in so far as it influences the velocity gradient in the boundary layer. 2. Experiments in glass tubes on cypris larvae of Elminius modestus and Balanus balanoides show that moderate velocity gradients exceeding 500 sec.-1 sweep the cyprids past the surface before they can attach. For large objects exposed to turbulent flow, the critical velocity gradient corresponds very approximately to a flow of 1-2 knots. 3. Attachment under conditions of water flow is accompanied by negative rheotaxy, and can occur equally in the light and in the dark. 4. Maximum attachment occurs at or below velocity gradients just great enough for the cyprid to be able to maintain position by swimming along the surface against the current. 5. Once the cyprid has attached it cannot be pulled off the surface even by gradients greatly in excess of those which prevent attachment. 6. Cyprids can migrate in all directions when exposed to moderate gradients, but they do so only with difficulty when the velocity gradient is high, particularly if the water is flowing in the same direction as that in which the cyprids are walking. The direction in which the cyprid migrates is altered only momentarily by changes in the direction of the current, the animal actively resisting the redistribution of forces acting on it. 7. No direct evidence is given in this paper on the influence of water currents on fixation, but a critical comparison with other published work suggests that fixation can occur in places where the velocity gradients are greater than those which limit attachment, provided the cypris is able to migrate there after attachment. 8. Moderate velocity gradients have little effect on the orientation at metamorphosis. Individuals tend to settle with the anterior end pointing downstream rather than in any other position. This orientation is the opposite from that which would be expected if the cyprid were passively orientated by the water current, but is likely to make subsequent feeding more efficient. 9. The ability to attach under conditions of water flow, and the tendency not to attach under stagnant conditions, may have an important influence on the animals' distribution and survival. 10. Solid particles in suspension may profoundly influence the behaviour, hence the results given in this paper may not be relevant to conditions where scouring takes place.

The Dawson Hill Member of the Grindstone Range Sandstone in the Flinders Ranges, South Australia

2010 ◽  
Vol 134 (1) ◽  
pp. 115-124 ◽  
Author(s):  
J.B. Jago ◽  
C.G. Gatehouse ◽  
C.McA. Powell ◽  
T. Casey ◽  
E.M. Alexander
Keyword(s):  
South Australia ◽  
Flinders Ranges

Studies of the yellow-footed rock-wallaby, Petrogale xanthopus Gray (Marsupialia : Macropodidae). Population studies at Middle Gorge, South Australia

1994 ◽  
Vol 21 (4) ◽  
pp. 473 ◽  
Author(s):  
AC Robinson ◽  
L Lim ◽  
PD Cantry ◽  
RB Jenkins ◽  
CA MacDonald
Keyword(s):  
Sex Ratio ◽  
Population Studies ◽  
South Australia ◽  
Effective Rainfall ◽  
Main Study ◽  
Exchange System ◽  
Two Phase ◽  
Flinders Ranges ◽  
Significant Bias ◽  
Males And Females

A mark-recapture study of Petrogale xanthopus at Middle Gorge in the southern Flinders Ranges revealed that between January 1979 and January 1984 the estimated known-to-be-alive population ranged from 11 to 20. During the main study, individuals living to an estimated age of six years were recorded. Captures of marked animals after completion of the main study revealed both males and females living to at least 10 years old. Births occurred throughout the year but there appeared to be an increase in births following periods of effective rainfall. For the whole study the sex ratio of pouch young did not vary significantly from 1:1. When individuals that gave birth more than once during the study were examined, there was a significant bias towards male young in the later births. It is suggested that this species has a two-phase reproductive strategy with the extra males, produced by older females, sustaining a male-exchange system with nearby colonies.

WOMEN OF THE ADNJAMATANA TRIBE OF THE NORTHERN FLINDERS RANGES, SOUTH AUSTRALIA

Oceania ◽  
1941 ◽  
Vol 12 (2) ◽  
pp. 155-162 ◽  
Author(s):  
C. P. Mountford ◽  
Alison Harvey
Keyword(s):  
South Australia ◽  
Flinders Ranges

Genetic Differentiation in Isolated Populations of Hakea carinata (Proteaceae)

1998 ◽  
Vol 46 (6) ◽  
pp. 671 ◽  
Author(s):  
G. J. Starr ◽  
S. M. Carthew
Keyword(s):  
Gene Flow ◽  
Habitat Fragmentation ◽  
Gene Diversity ◽  
South Australia ◽  
Similar Species ◽  
Isolated Populations ◽  
Plant Populations ◽  
Evolutionary Condition ◽  
Private Alleles

Fragmentation of the landscape by human activity has created small, isolated plant populations. Hakea carinata F. Muell. ex Meissner, a sclerophyllous shrub, is common in isolated fragments of vegetation in South Australia. This study investigated whether habitat fragmentation has caused restrictions to gene flow between populations. Gene diversity (HT = 0.317) is average for similar species but little is held within populations (HS = 0.168) and 46.9% of gene diversity is accounted for between populations. Estimates of gene flow are NM = 0.270 (based on FST) and NM = 0.129 (based on private alleles). Populations are substantially selfing (t = 0.111). Small isolated populations appears to be a long-term evolutionary condition in this species rather than a consequence of habitat fragmentation; however, population extinctions are occurring. Conservation will require the reservation of many populations to represent the genetic variation present in the species.

scholarly journals Karyotypes of three species of Hyperophora Brunner von Wattenwyl, 1878 (Tettigoniidae, Phaneropterinae) enable morphologically similar species to be distinguished

2019 ◽  
Vol 13 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Bruno Cansanção Silva ◽  
Lucas Henrique Bonfim Souza ◽  
Juliana Chamorro-Rengifo ◽  
Douglas Araujo
Keyword(s):  
Chromosome Number ◽  
Diploid Number ◽  
Sex Chromosome ◽  
Acrocentric Chromosome ◽  
Chromosome Morphology ◽  
Similar Species ◽  
Cerrado Biome ◽  
Cytogenetic Studies ◽  
Sex Chromosome System ◽  
The Difference

Phaneropterinae is the largest subfamily of Tettigoniidae, distributed across the globe. There are few cytogenetic studies regarding this group, as in the case of the genus group Aniarae, which represents only two karyotyped species. The current study aims to analyze cytogenetically three species of Hyperophora Brunner von Wattenwyl, 1878 from Brazil. The male diploid number of Hyperophoraminor Brunner von Wattenwyl, 1891 and Hyperophoramajor Brunner von Wattenwyl, 1878 is 2n♂= 31, whereas Hyperophorabrasiliensis Brunner von Wattenwyl, 1878 has shown 2n♂= 29. These three species possess an X0 sex chromosome system and telo/acrocentric chromosome morphology. The only species found in the Pantanal biome, H.brasiliensis, can be chromosomally distinguished from the Cerrado biome species H.major and H.minor, due to the difference in chromosome number (2n♂= 29 and 2n♂= 31, respectively).

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