According to the current study, the genus is divided into two species which are Orcaella brevirostris (Irrawaddy dolphins) and Orcaella heinsohni (Australian Snubfin dolphins) (Jefferson et al., 2008). Orcaella brevirostris and Orcaella heinsohni were differentiated according to their external features, habitat preference and genetic between the dolphins occurring in 5 fresh water systems and near shore water of Southeast Asia, the Bay of Bengal, east coast of India to Vishakhapatnam, coastal water of northern Australia and Southern Papua New Guinea (Beasley et al. 2005; Smith,
It tends to live in the North Eartern part of the US on colder streams and it's relater to the char. This actually makes it kind of a relative of the lake trout, but not quite a member of the same family. This fish is only found in very wilderness areas which makes it one of the favorite for trout anglers. In the places that is found you can be sure that the water is very clean and the ecology is as close as prestine as you can find it this days. The world record for this fish is was in Nipigon Riveer in Ontario, Canada back in 1918 a whooping 14 LB Brooke.
However, there are no distribution maps of sea urchins, except for the East Coast of Borneo. While many studies have been conducted on sea urchins and their importance in influencing marine ecosystems in other parts of the world, we have very little understanding on sea urchin distribution in Malaysia. Hence, the first objective of this study is to determine the distribution and abundance of sea urchins in Malaysia, as the first step to understand their role in Malaysia marine ecosystem. After all, the next step would be further exploration on the behaviour of these invertebrate as this will provide us a better understanding on how sea urchins interact with marine environment. Sea urchin behaviour is not well-studied in Malaysia, Although the migratory behaviour of a common sea urchins in Malaysia waters, Diadema setosum, has been studied but the home range and movement pattern were not identified, whereas other studies had proved urchins from genera Diadema possess nocturnal movement and feeding occurs only at night.
viridis in the neritic zone along the shores in Barangay Kanyuko, Dumanjug, Cebu while considering several assumptions (i.e. a) there is no birth, death or immigration during the study b) all animals have the same probability of being caught c) marks are not lost). The simplest case involves two capture sessions. In the first capture session, group of E. viridis was caught, marked and released. The population is then re-sampled on one subsequent occasion.
A big number of the dolphins live in salt water although other species are found in the freshwaters. According to Terrasi (2007), only a few of them are known to thrive well in the regions that have fresh water. Most dolphins have the tendency of swimming in the shallow sides of the ocean and can be found on the continental shelves. It is noteworthy that the species of the dolphin found in certain habitat is dependent on their location (Terrasi, 22). They also tend to prefer the areas that have warmers temperatures although they can be found in the colder regions mainly because of their need for food.