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Explanations for answers to quiz on what features of a nematocyst are important in its selection by a nudibranch:

Availability.  Yes.  If turnover time is short for a particular nematocyst in the cnidosac, then it would be advantageous if that type were plentiful in the prey.

Transport suitability.  Yes.  Fast-maturing nematocysts, for example, might be unsuitable simply because fewer of them would be available for transport to the cnidosacs.

Toxicity.  Possibly.  While highly potent nematocysts would seem to be desirable for the predator, ultimate selection of a particular nematocyst type might depend on a balance between availability, transport suitability, and toxicity.

Predator type.  Yes.  There is evidence that a nudibranch may select nematocysts based on a “risk-assessment” of the presence its own predators in its habitat (see Research Study that follows this quiz).  For example, a toxic penetrant type might be useful around predatory fishes or sea stars, or a tangling type where small predatory crustaceans are common.

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