FISHERY BULLETIN: VOL. 71. NO. 4 



32° 



30° 



28° 



20° 



114° 112° 110° 108° 



Figure 1. — Distribution of Acanthaster ellisii. 



106° 



stony corals in the Gulf occur. We found no 

 Acauthaster there on two visits, although we 

 dove over large areas of the two shallower reefs 

 and were towed behind a skiff over extensive 

 regions of the deeper reefs. Sport divers have 

 reported A. eUisii there, but the species is not 

 easily identifiable on casual observation, and 

 confusion with other asteroids, particularly 

 with the similarly sized, heavy-spined, and 

 abundant Nidorellia armata, is common. 

 Faulkner's report (pers. comm.) of two speci- 

 mens taken in relatively deep water outside the 

 main reefs at El Pulmo represents an anomaly 

 in the distribution of A. ellisii as otherwise 

 observed. 



Density 



Except at the islands near La Paz (Islas San 

 Jose, San Francisco, Partida, and Espiritu 

 Santo, to which we shall refer as the "island 

 complex") low densities of A. ellisii are sug- 

 gested by the numbers in Table 1. Dana 

 and Wolfson (1970) give 0.0045/ m^ (1/222 m^) 

 for those islands, and the nine specimens we 

 found in the thoroughly searched area of ap- 

 proximately 2,000 m- at "Pink Cliff station on 

 Isla Partida translate to an identical average. 

 The high density at Pto. Escondido, O.OOS/m^ 

 (1/200 m^), is deceptive, as we searched a 

 preselected area where the sea stars were con- 



930 



