Tag: lamprey
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Migration of Fishes
Introduction In life history of some fishes, population needs, like foraging & reproduction, can’t be met in single habitat. So, they travel periodically from one habitat to another & back after meeting the requirement, termed as fish migration. Causes: Sexual maturity, hormonal changes, instinct, predators, competition, food, light, temperature, pH, water currents, turbidity etc. The…
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Integumentary System (Skin and its derivatives)
Introduction The common structural pattern of both aquatic & terrestrial vertebrates of integument is… Epidermis Derived from Ectoderm Stratified i.e. consists of multi-layers of cells Dermis Derived mainly from mesoderm Formed of connective tissue Contain blood & lymph vessels, nerve & smooth muscle fibres, receptors and also special irregular pigment cells (chromatophores) Below dermis, subcutaneous…