Name: competent pluteus larva stage
ECAO ID: 0000510
Definition: "The competent pluteus larva is mainly characterized morphologically by the presence, on the ventral size, of still 8 arms and by the presence on the left side of the stomach of the rudiment that is now the size of or even bigger than the stomach. The rudiment further harbors by now five long primary podia (i.e. tube feet), five quartets of definitive spines located between the primary podia and five pairs of immature spines at the basis of the primary podia, while on the opposite side, i.e. on the right side of the larva, five to seven immature spines have further developed, supported by the genital plates, along with one to four pedicaellariae. At the level of the larva, in parallel, the anterior and posterior pairs of epaulettes have also considerably increased in size by now and even fused dorsally to the hydropore and to the anus respectively, thereby leaving exempt of cilia two lateral fields in between them. At the center of the left lateral field, the vestibular roof has also by now ruptured and this opening has created the vestibular pore, through which some primary podia of the rudiment protrude outside the larva and scrutinize the substrate looking for the adequate cues to begin metamorphosis. At that stage, the larva is thus exhibiting a typical substrate-test behavior, going to the sea bottom and scrutinizing the substrate. This behavior is characteristic of a larva named competent to metamorphosis, which it will accomplish providing that it is adequately stimulated by environmental factors."
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