ANDERSON and LINDNER: BIOLOGY OF ROYAL RED SHRIMP 



5 mm 



Figure 4. — Ventral view of thorax of adult female. 



a forward projecting cone-shaped protuberance 

 which Hes between the fourth pereiopods; the 

 paired triangular protuberances about midway 

 between the fourth and fifth pereiopods; and 

 the dome-shaped area between the fifth perei- 

 opods. 



Burkenroad (1936) described in detail the 

 petasma of H. robustus but did not illustrate it. 

 Figure 5 shows the petasma of H. robustus, 

 spread open to show its structure. 



Spermatophore 



Compared with the spermatophores of the 

 white shrimp (Penaeiis setiferus), the brown 

 shrimp (P. aztecus), and the pink shrimp (P. 

 duorarum) — all penaeid shrimp similar in size 

 to H. robustus — the spermatophore of the royal 

 red shrimp is exceptionally large. In fresh ma- 

 terial the spermatophore is bright yellow. 



5 mm 



Figure 5. — Petasma of male spread open to show 

 arrangement of rods and folds. 



Figure 6 shows a spermatophore in attached 

 position; Figure 7 shows a detached spermato- 

 phore. The winglike protuberances extend be- 

 tween the pereiopods, and the knobby and bristly 

 sections of the coxae help hold the spermato- 

 phore in place. A gluelike substance that ac- 

 companies the spermatophore when attached by 

 the male also helps hold it secure. The spermat- 

 ophores of royal red shrimp are much more 

 securely attached than those of the white shrimp 

 and are not easily dislodged. 



HABITS 



Anderson and Bullis (1970) contributed most 

 of our limited knowledge of the habits of this 

 deep-sea shrimp. Their observations from the 

 submarine Aluminmd were as follows: "Bottom 

 photographs had previously indicated that royal- 

 red shrimp stayed on the sea-floor surface, but 

 we saw numerous shallow furrows (1 to 3 ft 

 long) in the bottom in which royal-red shrimp 

 were partly buried. They apparently do not 

 burrow as deeply or completely as do brown and 

 pink shrimp. We believe the shrimp plow into 

 the bottom in search of food rather than pro- 

 tection, and that this feeding activity produces 

 the grooves or furrows. 



"When disturbed, the royal-red shrimp rise 

 gently from the furrows and swim in normal 



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