STRUCTURAL MODIFICATIONS OF SPERM FROM THE FIDDLER CRAB UCA TANGERI (DECAPODA) DURING EARLY STAGES OF FERTILIZATION

1992 ◽  
Vol 12 (4) ◽  
pp. 610-614
1992 ◽  
Vol 16 (2) ◽  
pp. 155-163 ◽  
Author(s):  
V POLYAKOV ◽  
D FAIS ◽  
I KIREYEV ◽  
O OLIVA ◽  
A RINALDI ◽  
...  

2007 ◽  
Vol 10 (2) ◽  
pp. 55-62 ◽  
Author(s):  
Joana M. Jordão ◽  
Ana F. Curto ◽  
Rui F. Oliveira

Author(s):  
Joana M. Jordão ◽  
Rui F. Oliveira

Excavation counts (absolute density), burrow counts and surface active individuals visual counts in a Uca tangeri population were compared. Population density estimated from burrow counts was not significantly different from population density estimated by excavation, but the population density estimated with visual counts was significantly lower than the absolute density. Ovigerous females should be the main cause of these differences because they frequently remain underground, but other groups of crabs are also contributing to this difference. Burrow counting is an accurate and quick non-invasive method for the census of U. tangeri. Other population measures (e.g. sex ratio) are not obtainable by burrow counting and only further understanding of the activity patterns of this species along the tide cycle, moon phase and reproductive season will allow visual counting of surface active individuals to be used as quick, efficient and non-invasive method for crab density and population structure estimation.


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