Sousa chinensis | Red List of Bangladesh Volume 2: Mammals

Taxa
Sousa chinensis | (Osbeck, 1765)
Publication
Red List of Bangladesh Volume 2: Mammals
NRL Record ID
327629
Location
Countries in Assessment
Bangladesh
Country ISO code(s)
BGD
Does the assessment cover a marine EEZ area(s)?
Off
Scope (Assessment)
National
Taxon
Taxonomic Group
Vertebrates
Taxonomic Group Level 2
Mammals
Assessed taxon level
Species
Taxonomic Notes
Humpback Dolphins in the IndoPacific are considered as of two species by some biologists: S. plumbea in the western Indian Ocean, from South Africa to the east coast of India and S. chinensis, from the east coast of India to China and Australia (Reeves e
Taxon distribution as listed in assessment
Discontinuously distributed throughout the shallow coastal waters of Indian and Pacific Oceans (Culik 2011, Reeves et al. 2008). Coastal and pelagic waters of the Bay of Bengal and waterways of the Sundarbans Mangrove Forest.
Habitats and Ecology
Ecological system type
Terrestrial system
No
Freshwater system
No
Marine system
No
Habitat
Habitat details as listed in assessment
Indo-Pacific Humpback Dolphins prefer areas strongly influenced by freshwater inputs. It is occurring further offshore in still shallow flats but where the water is more saline, warmer and turns from brown to green and the waterways of the Sundarbans Mangrove Forest containing high salinity. They are mostly social, makes group of 2 to 55 animals, avoids boats by diving toward different directions, splits into small groups or single animal. It breeds throughout the year (Culik 2011).
Is there a map available in assessment?
Yes, in the publication/on website
Assessed status
Asessment status in full
Least Concern
Assessment status abreviation
LC
Assessment rationale/justification
In 2002, a single group of Indo-Pacific Humpback Dolphins (Sousa chinensis) was reported by Smith et al. (2006) in a relatively high salinity channel of the southwest portion of the Sundarbans Mangrove Forest of Bangladesh. A total of six sightings of Sousa chinensis (mean group size 16.2, range 2 - 55) in the nearshore water of the Bay of Bengal was documented in 2004 (Smith et al. 2008). A single sighting of two individuals was made in the outer mouth of Naaf river in the southeast of Bangladesh in 2007. The Extent of Occurrence and Area of Occupancy are greater than threshold level of threatened categories. There was no information on habitat decline. Thus, this species has been categorized as Least Concern.
About the assessment
Assessment year
2015
Assessors/contributors/reviewers listed
Md. Zahangir Alom
Affliation of assessor(s)/contributors/reviewers listed on assessment
NGO
Academic
Assessor affiliation specific
Academic|NGO
Criteria system
Criteria system specifics
IUCN v3.1 + Regional Guidelines v4.0
Criteria system used
IUCN
Criteria Citation
IUCN (2012) IUCN Red List Categories and Criteria: Version 3.1. Second edition. Gland, Switzerland and Cambridge, UK: IUCN. iv + 32pp; IUCN (2012) Guidelines for Application of IUCN Red List Criteria at Regional and National Levels: Version 4.0. Gland, Switzerland and Cambridge, UK: IUCN. iii + 41pp.
URL (link) of redlist assessment or publication
http://iucnredlistbd.org/
Endemism
Endemic to region
No
Endemism Notes
Is an endemic?: No
Conservation
Conservation Measures

Conservation measures:
Conservation measures notes:
Required conservation measures:

Further information
History
Not assessed yet (IUCN Bangladesh 2000).
Scientific Name Kingdom Phylum Class Order Family Genus
Sousa chinensis Animalia Chordata Mammalia Cetartiodactyla Delphinidae Sousa