CBSE - IX - Biology - Diversity in Living Organisms
Physalia exhibit the highest degree of polymorphism. They have three kinds of polyploids :
- Gastrozooids for nutrition : Each gastrozooid possesses a long tentacle which may hangdown several metres below the pneumatophore. The gastrozooid feeds on fish. 2. Dactylozooids for defense : Dactylozooids are of various sizes. Each is a tubular mouthless individual with a long tentacle.They form a drift net for capturing fish for food which is drawn upto the gastrozooid by the contraction of tentacles. 3. Gonozooids for the asexual production of medusa: Gonozooids are branching blastostyles having leaf-like gonopores and male and female medusae .The male medusoids are reduced and remain attached but the female medusoids become detached and swim freely.
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