English: Sea Cow
Tagalog: Dugong
Scientific: Dugung Dugon
Population Status/Origin /Distribtution Habitat
Dugong live long and have very low productive rates They can live up to about 70 years and only reach sexual maturity at the age of 9 to 17 years. The male and female dugong can be differentiated from each other by lookinf at the distances between their anus, genital slit and umbilical scar. After mating, the female will give birth to only a single calf bonding as the calf stays near the cow for at least 18 months. during this time the calf will suckle from the cow's teats underneath the flipper.
The only time that the cow will concieve again is after 3 to 7 years. Helen Marsh assumess that if every female dugong in a given population gives birth every three years startung at the age of 10, an increase in the population of only 5% is expected per year.
Dugongs can be seen in tropical shallow coastal waters from 3 to 20 meters in depth where we can also find an abundance of seagrass. The Philippines is one of the 43 countries in the Indopacific where dugongs can be found which includes countries sech as Africa, India, indonesia, Papua New Guinea, Palau, Australia and the middle East. Today, only relict populatios remain in the Indo-Pacific, separated by large areas where populations are either close to extinction or are already extinct (Marsh1993)
There are several distinct populations in the world which were determined through mitochondrial DNA studies (Tikel 1995). One is the Asian dugong, another is the African dugong and several other populations in Autralia. It is estimited that there are only more than 100,000 dugongs in the whole world (Marsh pers. comm.)
Dugong were previously found in every island of the Philiippines. They were numerous along the country's lengthy coast. There is even one reord of a dugong caught from Manila Bay in the 18th century (Aragon1951). Documentation by early writers deliver a myriad of information, belifs and superstition about this animal. They were considered mysterious and human-like, although some described them as monstrous. Many historical accounts say that their body parts have medicinal powers.
It is evident that the dugongs have been exploited in the Philippines for a very long time.
There are no population counts in the country. In palawan, where most studies have been done. the population is described as sparse and low in density (Kataoka et al. 1995 and Nishiwaki et al 1979). Dugongs form large herbs of up to hundreds of animals. Usually, they are only seenalone or in pairs.
Dugongs have become extinct in many aresa in the Philippines. Most of the remaining of the dugongs in the country can be found in Palawan. Twoother areas with possible viable populatios are the eastern Luzon coast (Isabela-Quezon) ans southern Mondanao. There are alsoindications that dugongs may still exist in Bicol, Catanduanes, Romblon, Mindoro, Caluya Islands and Cuyo. they are probably rare or extinct in the western Lizon coast, norther Mindanao, Samar and the visayas(Kataoka et al.1995)
Description
Like People and other mammals, thedugong is warm-blodded, has hairs breaths air, and the mother suckles their young. In fact, nothing comes closest to the description of mermainds than this animal. This has led to the common belief that the dugong is the true mermaid of the seas.
An adult dugong can grow to about 3 meters in lenght and weigh more than 400 kilograms. Nweborns rea a little over a meter, while mature animals measure at least 2.5 meters in lenght (Marsh et al. 1984). The dugong's body is torpedo-shaped with small filppers and a whale-like tail. Its color is grayish-brown.
Dugongs swim slowly, are shy and evasive. They move along coasts and between islands. Their movement is affected by the tide, weather, season, availability of food, and himan disturbance. They need to breathe air on the surface of the water every one to four minutes. The dugong is a very gentle animal that lives peacefully in our seas wihtout causing harm to people or other marine life.
Behavior
The dugong's primary food is the grass. These are nine species found in Palawan (PCP surveys) all of which are eaten by the dugong. However, softer, younger and smaller species, e.g. Halophila and Halidule, are preferred instead of older leaves or more fibrous species, eg, Enhalus(Lanyon 1993). The dugong has also been observed to feed on seaweeds and some invertebrates (Marsh 1991)
The dugong uses its specialized snout to eat. Its snout is conveniently positioned at the ventral side of the body and can change in size and shape. it has lots of short and thick hairs. This allows the dugong to feed off the sea bottom, eating not only the leaves of the seagrasses but their roots and rhizomes as well. this leaves a distinguishable path in the seagrass bed called dugong feeding trails or trenches. These footprints are used in identfying areas where dugong feed.
Because os the dugong's large size and the seagrasses low nutrient content, an adult can consume more than 25 kgs af segrass in a day (Lanyon et al. 1989 and Heinsohn et al. 1997).