FAO Species Identification Guide for Fishery Purposes Western

896 Shrimps and Prawns
8a. In males, each distomedian projection of petasma forming a broad outward curved distal
tooth; in females, anterior plate of thelycum with a pair of anterolateral rounded tubercles,
each lateral plate with a short anteromedian ridge and a patch of setae . . . . . Metapenaeus insolitus
8b. In males, each distomedian projection of petasma without distolateral teeth; in females,
anterior plate of thelycum without tubercles, lateral plates with long ridges and without
patches of setae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .→ 9
9a. In males, distomedian projections of petasma concealing distolateral ones in ventral
view, merus of fifth leg with a long inward curved spiniform process followed by a distinct
row of tubercles; in females, ridges on lateral plates of thelycum subparallel or forming
posteriorly distinctly inward curved processes . . . . . . . . . . . . . . . . . . . . . . . . . . → 10
9b. In males, distomedian projections of petasma not concealing distolateral ones in ventral
view, merus of fifth leg with a tubercle; in females, ridges on lateral plates of thelycum
closer to each other posteriorly and without distinctly inward curved processes . . . . . . . . → 11
10a. Rostrum armed with 7 to 9 upper teeth; in males, distomedian projections of petasma
reaching about as far as distolateral ones; in females, lateral plates of thelycum with
strongly raised crescent-shaped ventral ridges, coming close together posteromedially
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Metapenaeus conjunctus
10b. Rostrum armed with 8 to 12 upper teeth; in males, distomedian projections of petasma
reaching well beyond distolateral ones; in females, lateral plates of thelycum with
strongly raised externolateral edges, a wide space separating them . . . . . . . Metapenaeus ensis
11a. In males, distomedian projections of petasma directed forward, their inner margins
almost parallel, tubercle on merus of fifth leg slightly bent inward; in females, ridges on
lateral plates of thelycum curved outward posteriorly . . . . . . . . . . . . Metapenaeus papuensis
11b. In males, distomedian projections of petasma directed anterolaterally, diverging, with
distinct longitudinal grooves, tubercle on merus of fifth leg slightly bent outward; in
females, ridges on lateral plates of thelycum curved inward posteriorly . . . . Metapenaeus elegans
12a. Branchiocardiac crest reaching posterior extension of hepatic spine; in males, distomedian
projections of petasma crescent-shaped; in females, posterior transverse ridge
behind thelycum with 2 anterolateral rounded projections . . . . . . . . . . . .Metapenaeus affinis
12b. Branchiocardiac crest ending near posterior 1/3 of carapace; in males, distomedian
projections of petasma never crescent-shaped; in females, posterior transverse ridge
behind thelycum without projections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . →13
13a. In males, distolateral projections of petasma widening distally, distomedian projections
not reaching as far as distolateral ones; in females, anterior plate of thelycum very broad
in its distal half and very narrow posteriorly, lateral plates fused and rounded W-shape
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Metapenaeus demani
13b. In males, distolateral projections of petasma tapering distally, distomedian projections
exceeding distolateral ones; in females, anterior plate of thelycum about same width on
anterior and posterior margins, lateral plates not rounded W-shape . . . . . . . . . . . . . . . →14
14a. In males, distomedian projections of petasma tubular and diverging; in females, anterior
margin of anterior plate of thelycum with 2 fang-like teeth and a median indistinct
tubercle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Metapenaeus dalli
14b. In males, distomedian projections of petasma either tubular and subparallel or laminose
and diverging; in females, anterior margin of anterior plate of thelycum with 3 tubercles . . . . . →15
15a. In males, distomedian projections of petasma tubular and almost parallel, their distal
part twisted dorsoventrally; in females, distal margin of anterior plate of thelycum
triangular, median tubercle more prominent than lateral ones . . . . . . . . Metapenaeus bennettae
15b. In males, distomedian projections of petasma laminose and diverging; in females, distal
margin of anterior plate of thelycum convex, all tubercles of subequal size . . Metapenaeus moyebi
16a. Telson armed with 4 pairs of large movable spines . . . . . . . . . . . . . . Metapenaeus macleayi
16b. Telson without large movable lateral spines (though sometimes with many minute
spinules) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . →17