Palaemon has

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Palaemon has 19 pairs of appendages.

Palaemons are decapod crustaceans. They belong to the family Palaemonidae in the Animal Kingdom. They are aquatic animals that live in rivers, lakes, freshwater streams, and ponds. The decapod crustaceans possess 38 appendages (19 pairs). The appendages are external body parts. Out of the 38, 10 appendages are considered legs. The appendages are biramous types and consist of two branches. Each appendage is consists of a base (protopodite) and the inner endopodite and outer exopodite.

The body Palaemon consists of the anterior Cephalothorax (head and thorax) region and the posterior abdomen. The list appendages are as follows:

(1) Appendages in the head region:

(i) Antennules: 1 pair (2 in numbers)
(ii) Antennae: 1 pair (2 in numbers)
(iii) Mandibles: 1 pair (2 in numbers)
(iv) Maxillula: 1 pair (2 in numbers)
(v) Maxillae: 1 pair (2 in numbers)

2) Appendages in the thoracic region:

(i) First maxillipeds: 1 pair (2 in numbers)
(ii) Second Maxillepeds: 1 pair (2 in numbers)
(iii) Third Maxillepeds: 1 pair (2 in numbers)
(iv) Fourth Maxillepeds: 1 pair (2 in numbers)
(V) Fifth Maxillepeds: 1 pair (2 in numbers)
(iv) Walking legs: 3 pairs (10 in numbers)

(3) Abdominal Appendages:

(i) Pleopod: 5 pair (10 in numbers)
(ii) Uropods: 1 pair (2 in numbers)

Examples:

Baltic prawn (Palaemon adspersus)
Rockpool shrimp (Palaemon elegant)
Giant tiger prawn (Penaeus monodon)