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I would like to know how many appendages the arthropod Phronima sedentaria has, and how they are arranged. It's not hard to find picture references, but Phronima's transparency makes it difficult to tell from live photos, while what drawn diagrams and text descriptions I've been able to find diverge wildly.

From what I've been able to determine, it has a bulbous head which may or may not have antennae, near to which are two to four pairs of limbs. There is a small gap, then a much longer pair of limbs ending in claws, followed potentially by a second longer pair, and then two to four shorter pairs of limbs. The tail is lined by three pairs of swimmerets, possibly tipped with paddles or bristles.

The best possible answer for this would be a picture like this one, with the assurance that it does indeed represent Phronima sedentaria accurately, though I would be happy with a confirmation of appendage count. Additionally, while I would prefer information about Phronima sedentaria specifically, I can make do with such information about any member of the genus so long as it is specific.

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After finding some higher-quality images/videos with some views of the creature from the front, I can say that the image I linked is mostly accurate, if lacking in detail. There does appear to be a set of antennae, though they are significantly shorter than the legs, the front two pairs of legs are shorter than the others and end in small claws, and are positioned more 'underneath' than 'to the side of' the body relative to the other legs. The reason for the confusion seems to have been a combination of the different position of the front four legs, some pictures of other Phronima species misnamed as sedentaria, and that the antennae appear to be able to fold in close to the head, making them nearly invisible.

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