Community structure of the fiddler crab (Uca spp.) at Bahak Indah Beach, Tongas, Probolinggo – East Java
Abstract
The fiddler crab (Uca spp.) is a type of animal belonging to the crustacean group that lives on
the coast of Bahak Indah, Tongas, Probolinggo. The high level of anthropogenic activity on the beach of Bahak
Indah makes the fiddler crab community increasingly depressed and its habitat decreasing. The purpose of
this study was to compare the community structure of fiddler crabs at Bahak Beach, Tongas, Probolinggo. The
study was conducted in January – February 2022. The determination of observation stations was purposive
based on the consideration of the presence and absence of mangrove vegetation. Sampling of fiddler crabs
used a systematic sampling method using transects and plots. Community structure data analysis includes
diversity, uniformity, and dominance indices displayed in graphical form. Based on the results of the study
found 4 types of fiddler crabs in Bahak Indah Beach, namely Uca cryptica, Uca perplexa, Uca coarctata, and Uca
dussumieri. The value of diversity on the beach with mangrove habitat is in the medium category, while on
the beach habitat without mangrove vegetation it is in the low category. The uniformity value obtained in
mangrove habitats is in the high category, while in coastal habitats without mangrove vegetation it is found
in the medium category. On the other hand, the dominance index value is in the low category in coastal
habitats with mangrove vegetation, and the moderate category in coastal habitats without mangrove
vegetation. The relationship between the Diversity (H') of the fiddler crab and the environmental conditions
of the Bahak Indah Beach waters is that it has a positive correlation with water pH parameters with sufficient
correlation and soil pH with a strong correlation. While the correlation with temperature parameters is
strong but negative. Likewise, salinity is quite strong but negative.