. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. maxillule Figure 6. Coordination of maxillule and mandible movements during phase 2 of ingestion of an Arteinui metanauplius by a first-stage PUiceiron wosnessenskii zoea. Approximate duration: to s. sequences, phase 1 of ingestion was shortened to merely the fling and capture steps, which were followed immediately by the maceration associated with phase 2. Recorded phase 1 duration ranged from to s in sequences involving only a single metanauplius. and from to s in sequences involving two or more m
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. maxillule Figure 6. Coordination of maxillule and mandible movements during phase 2 of ingestion of an Arteinui metanauplius by a first-stage PUiceiron wosnessenskii zoea. Approximate duration: to s. sequences, phase 1 of ingestion was shortened to merely the fling and capture steps, which were followed immediately by the maceration associated with phase 2. Recorded phase 1 duration ranged from to s in sequences involving only a single metanauplius. and from to s in sequences involving two or more meta- nauplii. Mean durations were (;i = 14; SD = ) and (n = 5; SD = ) s respectively. Phase 2. This phase of ingestion involves the maxillules, mandibles, and labrum. Phase 2 begins with the first contact of the metanauplius with the mandibles and ends with the loss of direct contact with the prey item by the basal endites of the maxillules. The maxillules, after manipulating the metanauplius into position in phase 1, begin pushing the prey toward the mouth, bringing it into contact with the mandibles. In one sequence, phase 2 was initiated by re- peated nudging of the metanauplius into and out of range of the mandibles by the maxillules. The maxillules and labrum press the metanauplius against the mandibles as the latter tear and grind the prey on its way into the mouth. Two separate ratcheting mechanisms were observed, each of which maintains a steady net movement of the metanauplius into the mouth, while enabling the appendages to renew points of contact for leverage. First, the maxillules and mandibles alternate motions, maintaining a firm grip on the metanauplius as it is masticated (Fig. 6). The maxillules press the prey against the mandibles as they shred bits of tissue with their rolling motions. The mandi- bles then hold the metanauplius as the maxillules regrasp it once every two or three mandibular rotations, or as seen in two sequences, with each man
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
