Eel Observation

4.Disscussion

4.1 Behavior observation of presence in water column and bury activity

Burial activity is one of the most important aspect of eel lifestyle. Despite on fact that in our experiment most of eels decided to stay in water column , about 14 eels at the end of trials were partly present in a water column. Most of them give preference to medium and large size gravel , both with 5 eels respectively. Suitable size of holes between gravel might be a reasonable explanation why eels choose especially this type of habitat.

It is sensible that we did not observe any of burring eel in small gravel because of subtract tight composition, which do not allowed eels to bury in it. Explanation why there is so small number off burying eels in small

Good substacte,with fine coarse wholes is a perfect habitat which help young eels be less vulnerable and increase their chances for survivor. That also might explain why we bserved that juvenile eel had a lower preference for sediment substrata with grain sizes .It is because they simply could not bury(GS). However, in a results he had some who were found in this habitat,and it might confuse the reader. Those eels we found between the box with subtract and plastic quadrant. Expecially this behaviour we found in a smaller eels because of their tiny size and probably hiding from other larger

It is strongly recommended to avoid those activation to protect stream environment for eel natural habitat.(17)

Thus, in light of the results in this study, it can be assumed that excavation and habitat destruction observed in recent years has probably reduced the quantity and quality of suitable habitats for juvenile eel, which could be negatively affecting both ecologically and economically.

4.5 Further studies

Various observations European eel life history should be describe not as truly catadromous, but "facultative or semi catadromous". Due to fact that European eel were found in different waters such as freshwater,brakish and coastal,and freshwater phase is not be a essential part of their life history, could not make them not truly catadromous species.(18)

This is the only experimental study until now, as far as we know, that contribute to the understanding the habitat choice of eel juveniles in brackish salinity water .Therefore further studies should be taken in order to contribute better understand about substrate selection in all Anguillae group.