r 



Figure 43. — Maorohraohium acanthurus (Wiegmann). Animal in lateral view (after Hedgpeth, 1949). 



Abdomen smooth; pleura of fifth segment end- 

 ing in an acute point. Telson 1.5 times length 

 of sixth segment, with pairs of dorsal spines at 

 middle and three-fourths of length; posterior 

 margin ending in sharp median point flanked by 

 two pairs of spinules, inner pair overreaching 

 median point. 



Measurements. — Length of body : male, 166 

 mm.: ovigerous females, 36 to 110 mm. 



Figure 44. — Macrobrachium acanthurus (Wiegmann). 

 A, second leg of adult male; B, fingers of second leg 

 of adult male (part of hairs removed) : A, B, X 0.75 

 (after Holthuis, 1952). 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 

 T63M)49 O — 65 — —5 



Variations. — The rostrum may vary in length 

 and shape. Adult females and young males have 

 second legs shorter, more slender, less spinulose 

 and pubescent than adult males. 



Color. — Green or pale yellow with red speckles; 

 carapace with middorsal stripe of red or brownish 

 orange and occasionally with irregular red bands 

 laterally; chelipeds greenish becoming blue dis- 

 tally, articulations orange; abdomen with mid- 

 dorsal stripe similar to carapace, pleura green 

 with blue edges and striped with red ; eggs green 

 (Hedgpeth, 1949; Schmitt in Holthuis, 1952). 



Habitat. — The species lives in coastal rivers 

 and bays, usually near brackish water, but some- 

 times quite far upstream; 97 miles from mouth 

 of Rio Grande River in Texas (Hedgpeth, 1949). 



Type locality. — Brazilian coast. 



Known, range. — Neuse River estuary, N.C., to 

 Rio Grande do Sul, Brazil; West Indies. 



Remarks.— This species probably has a later 

 breeding season than Macrobrachivm ohione 

 (Hedgpeth, 1949). The recent discovery of M. 

 acanthurus in the Neuse River estuary of North 

 Carolina may indicate an active northward ex- 

 tension of range similar to the case of M. ohione. 



53 



