Optimal Salinity for Head-Starting Northern River Terrapins (<i>Batagur baska</i> Gray, 1831)
Northern river terrapins (<i>Batagur baska</i> Gray, 1831) are Asia’s largest turtles living in both freshwater and brackish water. In the current study, the optimal salinity for head-starting programs of this critically endangered species was investigated in order to serve the...
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MDPI AG
2019-10-01
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| Series: | Animals |
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| Online Access: | https://www.mdpi.com/2076-2615/9/11/855 |
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| author | Suthep Jualaong Anida Songnui Karun Thongprajukaew Santi Ninwat Suwandee Khwanmaung Waraporn Hahor Pairat Khunsaeng Hirun Kanghae |
| author_facet | Suthep Jualaong Anida Songnui Karun Thongprajukaew Santi Ninwat Suwandee Khwanmaung Waraporn Hahor Pairat Khunsaeng Hirun Kanghae |
| author_sort | Suthep Jualaong |
| collection | DOAJ |
| description | Northern river terrapins (<i>Batagur baska</i> Gray, 1831) are Asia’s largest turtles living in both freshwater and brackish water. In the current study, the optimal salinity for head-starting programs of this critically endangered species was investigated in order to serve the well-being of turtles before release to natural habitat. Forty-eight terrapins (54.64 ± 0.18 g initial body weight) were randomly distributed to four salinity levels (0, 4, 8, and 12 ppt) and reared for eight weeks, using three replicates with four terrapins each. At the end of rearing trial, growth performance and feed utilization parameters were superior in terrapins reared at 4 ppt, followed by 8 ppt in the rank order of treatments. Negative stress responses were observed in terrapins reared at 12 ppt, as the fecal activity of amylase-to-trypsin ratio was changed significantly, but not that of proteolytic enzymes. The fecal thermal transition properties indicated an abundance of nutrients in the post-absorptive phase for terrapins reared at 4 ppt, followed by the 8 ppt treatment group. The preferred 4 ppt salinity had no negative effects on the health status of the terrapins in terms of carapace elemental composition or hematological parameters. Second-order polynomial regression suggests 4.35 ppt as the optimal salinity for maximal weight gain. Findings from the current study could be directly used in ex situ conservation programs of northern river terrapins before release to natural habitat. |
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| last_indexed | 2024-12-22T04:54:12Z |
| publishDate | 2019-10-01 |
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| series | Animals |
| spelling | doaj.art-bf0f2a51132541129616107e5d9e1ccc2022-12-21T18:38:25ZengMDPI AGAnimals2076-26152019-10-0191185510.3390/ani9110855ani9110855Optimal Salinity for Head-Starting Northern River Terrapins (<i>Batagur baska</i> Gray, 1831)Suthep Jualaong0Anida Songnui1Karun Thongprajukaew2Santi Ninwat3Suwandee Khwanmaung4Waraporn Hahor5Pairat Khunsaeng6Hirun Kanghae7Marine and Coastal Resources Research and Development Center, Lower Gulf of Thailand, Songkhla 90100, ThailandTrang Coastal Fisheries Research and Development Center, Trang 92150, ThailandDepartment of Applied Science, Faculty of Science, Prince of Songkla University, Songkhla 90112, ThailandMarine and Coastal Resources Research and Development Center, Lower Gulf of Thailand, Songkhla 90100, ThailandSatun Inland Aquaculture Research and Development Center, Satun 91110, ThailandDepartment of Applied Science, Faculty of Science, Prince of Songkla University, Songkhla 90112, ThailandPattani Coastal Aquaculture Research and Development Center, Pattani 94150, ThailandPhuket Marine Biological Center, Phuket 83000, ThailandNorthern river terrapins (<i>Batagur baska</i> Gray, 1831) are Asia’s largest turtles living in both freshwater and brackish water. In the current study, the optimal salinity for head-starting programs of this critically endangered species was investigated in order to serve the well-being of turtles before release to natural habitat. Forty-eight terrapins (54.64 ± 0.18 g initial body weight) were randomly distributed to four salinity levels (0, 4, 8, and 12 ppt) and reared for eight weeks, using three replicates with four terrapins each. At the end of rearing trial, growth performance and feed utilization parameters were superior in terrapins reared at 4 ppt, followed by 8 ppt in the rank order of treatments. Negative stress responses were observed in terrapins reared at 12 ppt, as the fecal activity of amylase-to-trypsin ratio was changed significantly, but not that of proteolytic enzymes. The fecal thermal transition properties indicated an abundance of nutrients in the post-absorptive phase for terrapins reared at 4 ppt, followed by the 8 ppt treatment group. The preferred 4 ppt salinity had no negative effects on the health status of the terrapins in terms of carapace elemental composition or hematological parameters. Second-order polynomial regression suggests 4.35 ppt as the optimal salinity for maximal weight gain. Findings from the current study could be directly used in ex situ conservation programs of northern river terrapins before release to natural habitat.https://www.mdpi.com/2076-2615/9/11/855carapacedigestive enzymeelemental compositionfecesfeed utilizationgrowthhead-starting programhematological parameter |
| spellingShingle | Suthep Jualaong Anida Songnui Karun Thongprajukaew Santi Ninwat Suwandee Khwanmaung Waraporn Hahor Pairat Khunsaeng Hirun Kanghae Optimal Salinity for Head-Starting Northern River Terrapins (<i>Batagur baska</i> Gray, 1831) Animals carapace digestive enzyme elemental composition feces feed utilization growth head-starting program hematological parameter |
| title | Optimal Salinity for Head-Starting Northern River Terrapins (<i>Batagur baska</i> Gray, 1831) |
| title_full | Optimal Salinity for Head-Starting Northern River Terrapins (<i>Batagur baska</i> Gray, 1831) |
| title_fullStr | Optimal Salinity for Head-Starting Northern River Terrapins (<i>Batagur baska</i> Gray, 1831) |
| title_full_unstemmed | Optimal Salinity for Head-Starting Northern River Terrapins (<i>Batagur baska</i> Gray, 1831) |
| title_short | Optimal Salinity for Head-Starting Northern River Terrapins (<i>Batagur baska</i> Gray, 1831) |
| title_sort | optimal salinity for head starting northern river terrapins i batagur baska i gray 1831 |
| topic | carapace digestive enzyme elemental composition feces feed utilization growth head-starting program hematological parameter |
| url | https://www.mdpi.com/2076-2615/9/11/855 |
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