The hypoxia adaptation strategy of the big-belly seahorses (Hippocampus abdominalis) with tuft gills
Hypoxia tolerance is a critical trait in fish breeding, however, the mechanisms underlying hypoxia regulation in the tuft gills of seahorses remain unclear. In this study, we compared the gill structures of the big-belly seahorses (Hippocampus abdominalis, BBS) with lamellae gill fish and evaluated...
Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-03-01
|
| Series: | Aquaculture Reports |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S235251342400632X |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Hypoxia tolerance is a critical trait in fish breeding, however, the mechanisms underlying hypoxia regulation in the tuft gills of seahorses remain unclear. In this study, we compared the gill structures of the big-belly seahorses (Hippocampus abdominalis, BBS) with lamellae gill fish and evaluated the effects of hypoxia on BBS. The average oxygen tension threshold for loss of equilibrium (LOEcrit) of BBS (2.68 mg·L−1) was higher than that of the common hypoxia-sensitive fish. Compared with the normoxia group, the duration of stationary, irregular swimming, curled tail, lying down behaviors, and respiratory rate significantly (P < 0.05) increased, while the duration of swinging and swimming behaviors significantly (P < 0.05) decreased in response to hypoxia. After 4- or 7-days of hypoxia treatment, the red blood cell counts, SOD, CAT, GSH, and T-AOC of BBS were significantly (P < 0.05) higher than those in the normoxia group. Notably, when BBS were exposed to hypoxia, the relative surface area of the exposed distal gill filaments significantly increased (P < 0.05). Meanwhile, no significant (P > 0.05) changes were observed in the medial and proximal regions. Ultimately, we identified 5 significantly (P < 0.05) down-regulated (itgav, itga6a, itga1, pcna, and adcy9) and 5 significantly (P < 0.05) up-regulated (gusb, src, cdc20, ccnb1, and plk1) core hub genes related to gill remodeling. This study demonstrates that BBS is sensitive to hypoxia, and its unique tuft gills respond to hypoxia through local gill remodel, providing valuable insights for the breeding of hypoxia-tolerance seahorses. |
|---|---|
| ISSN: | 2352-5134 |