Palaemon Weber, 1795

Walker, T. M. & Poore, G. C. B., 2003, Rediagnosis of Palaemon and differentiation of southern Australian species (Crustacea: Decapoda: Palaemonidae), Memoirs of Museum Victoria 60 (2), pp. 243-256 : 247

Palaemon Weber, 1795

Palaemon Weber, 1795: 94 .— Holthuis, 1950: 42–44 (extended diagnosis).— Holthuis, 1993: 112–114 (synonymy).

Diagnosis. Rostrum well developed, toothed dorsally and ventrally, without an elevated basal crest; upper margin bearing single row of setae between dorsal teeth. Carapace smooth, bearing distinct branchiostegal spine and groove; branchiostegal spine usually situated on carapace edge but may be set back; groove usually running straight back from carapace edge in a shallow arc but may rise upwards and over spine before continuing posteriorly or, in P. intermedius , into and over but not past its posterior edge. Antennal spine generally strong, on anterior margin of carapace some distance below rounded lower orbital angle. Mandibular palp usually of 2 or 3 articles, but may be absent. Eyes distinctly pigmented, cornea well developed. Anterior margin of antennular peduncle rounded, anterolateral spine small. First pleopod of male without or with rudimentary appendix interna on endopod. Propodus of fifth pereopod with several transverse rows of setae on distal part of the posterior margin. Telson with 2 slender median setae on posterior margin. Pleura of fifth abdominal somite usually ending in small sharp point.

Remarks. The revised diagnosis allows for the variable position of the branchiostegal spine and accommodates the hepatic position of this spine seen in some Australian species.