Prelims: Indian Geography (species, River), Bull shark, Vaitarna River, IUCN Green Status Assessment
Mains: General Studies-I, Important Geophysical Phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., geographical features and their location-changes in critical geographical features (including water-bodies and ice-caps) and in flora and fauna and the effects of such changes.
Why in the News ?
Recently, the bull shark attacked a fisherman in Vaitarna river at Dongripada in Maharashtra’s Palghar district was the first sighting of a bull shark 40km upstream in the river.
Source: HT
Key Facts 🗝️
- Bull Shark
- Conservation status: IUCN – Vulnerable
📌 FYI on Prelims:
- IUCN Green Status Assessment
- The IUCN Green Status classifies species into nine Species Recovery Categories, indicating the extent to which species are depleted or recovered compared to their historical population levels.
- Each Green Status assessment measures the impact of past conservation on a species, a species’ dependence on continuing support, how much a species stands to gain from conservation action within the next ten years, and the potential for it to recover over the next century.
About:
- Bull Shark
- They’re known to be aggressive towards humans and are thought to be one of the most dangerous shark species in the world.
- Habitat: Tropical coastal areas worldwide, including shallower waters along coastlines.
- Unique ability to tolerate freshwater and saltwater habitats, meaning they can sometimes be found venturing into rivers and traveling great distances upstream.
- Reproduction: Through viviparity, the process in which the embryo develops within the mother’s body, leading to live birth.
- Vaitarna River:
- It is one of the west flowing rivers in the region North of Mumbai and South of the Tapi River.
- Origin: Originates in the Trimbakeshwar Hills of Nasik district of Maharashtra.
- It receives most of the rainfall from the South West monsoon during June to October. Almost 98% of the annual rainfall of the basin is received during this period.
- Tributaries: The main tributaries are Pinjal, Ganjai, Surya, Daharji and Tansa.
- The catchment area of Vaitarna basin completely lies in Thane and Nasik districts of Maharashtra.
- Drain: An area of 2019 sq km before it falls in Gulf of Khambhat.
UPSC CSE EXAMS Corner
Prelims: PYQ/FAQ
Q. Among the following, which one lays eggs and does not produce young ones directly? (2008)
A) Echidna
B) Kangaroo
C) Porcupine
D) Whale
Ans: a. Echidna
Explaination:
- Echidnas, sometimes known as spiny anteaters, belong to the family Tachyglossidae in the monotreme order of egg-laying mammals.
- The four extant species of Echidnas and the platypus are the only living mammals that lay eggs and the only surviving members of the order Monotremata.
- Echidnas evolved between 20 and 50 million years ago, descending from a platypus-like monotreme, which was aquatic, but echidnas adapted to life on land.
