pear to overlap somewhat. The few stations from 

 which tropical species have been talcen in this 

 region may be under the Florida Current at some 

 times but not at others, owing to the meanderings 

 of the current. Also, the average bottom tempera- 

 ture is higher than it is nearer shore or in the 

 deeper water of the slope. 



Table 1 indicates the affinities of the various spe- 

 cies in relation to their geographic ranges and to 

 the biotic provinces of the shelf. The distribution 

 of North Carolina asteroids largely follows the 

 distribution pattern shown by Cerame- Vivas and 

 Gray (1966) for other benthic species of the area. 



Table 1. — Asleroidea known to occur in North Carolina 



waters, their geographic affinities, and areas of distribution 



on the Continental Shelf 



Geographic affinity and species 



Biotic Provinces 



Virginian Carolinian Caribbean 



Northern and Southern: 



Coronaster hriareus 



OdoJttaster tiispidus 



Astertas forhtsii 



Astropecten artlcidatus. 



Lliidia clathrata 



Tethyaster vestitus 



X 

 X 

 X 

 X 

 X 



X 

 X 

 X 

 X 



X 

 X 

 X 



Northern: 



Asterias vitlgaTis 



Ctenodiscus crispatus 



Henricia sa uguinolenta. _ 



Lfptas'erias tcnera 



Peltaster pJanu.f;^ 



Porania insignis 



AstropecUn americanus. 



Aslerins tanneri 



yfediastfT bandii 



X 

 X 

 X 

 X 

 X 

 X 

 X 

 X 



X 

 X 

 X 



Southern: 



f cbinaMer seiitii^ 



Echivaster spinulosus 



Thyra-fter serpfjifarius 



Astropecten diipheatus 



Coseiiiasterias leninspina. 



Liiidin alteTualn 



Astropecten nilidus 



Astropecten ni/llirtQi 



Kctiinaster firasiUensis 



Goninster americanus 



Linckia bourieTJ 



Li'.idia bernasconiae - 



Luidia elegans 



Narcissia trigonaria 



Oreaster retien.latus 



PlmtfiasteT dentatus 



SolastfT caribbaeus 



Stephanasterias gracilis 



X 

 X 

 X 

 X 

 X 

 X 



X 

 X 



X 

 X 

 X 

 X 

 X 

 X 

 X 

 X 

 X 

 X 

 X 

 X 

 X 



The entire benthic faima is largely "southern," 

 that is, more species range southward from North 

 Carolina than range northward. Foui-teen of the 

 33 asteroids, all tropical or subtropical, occur only 

 in the Carilibean Province. No strictly tropical 

 species gets into the Virginian Province. On the 

 other hand, some of the northern speeies do find 

 their way into the Carolinian Province and some- 

 times into tlie Caribbean Province, especially at its 

 northern end. Only three starfishes were found in 



all three biotic areas — but not in equal abundance 

 in all of them. For example, Luidia clathrata and 

 Astropecten articulatu.s are much more abundant 

 in the Carolinian Provmce than in either the Vir- 

 ginian or Caribbean Province. The only "north- 

 ern" species not collected in the Virginian Prov- 

 ince is Mediaster bairdii. Thus far this species has 

 been collected only from the edge of the shelf off 

 Cape Lookout. Similarly, Tethya.ster, a species 

 that ranges both north and south of North Caro- 

 lina, has been taken only in the Caribbean 

 Province. 



IDENTIFICATION OF SPECIES 



Although tlie following keys cover the sea-stars 

 now known to oc«iu' on the North Carolina shelf, 

 it would not be surprising if additional species, es- 

 pecially Caribbean species, were collected from 

 time to time. Tecluiical terms are defined in the 

 glossary and illustrated in figure 4. Additional 

 details of morphology may be obtained from 

 Hyman's (1955) vohmie on the Echinodennata, 

 from which much of the tenninology used here 

 has been taken. 



GLOSSARY 



AbactiuaJ : Upper or aboral surface opposite mouth 



and ambuiacral grooves. 

 Aboral: See abactinal. 

 Actinal: Oral or lower surface on which mouth 



and ambuiacral grooves are situated. 

 Adambulacnim: Ossicle in series bordering am- 

 buiacral groove adjacent to ambuiacral 



ossicles. 

 Alveolar pedicellaria: Pedicellaria witli two 



valves which are partly sunken into a 



depression on a plate. 

 Ambulacrum: Groove on the actinal surface of 



the arm, from moutli to ann tip, containing 



the tube feet. Also, a plate of the double series 



flooring the ambuiacral groove. 

 Ampulla: Eounded (single) or bilobed (double) 



sac above each tube foot. 

 Bivalved pedicellaria: Pedicellaria liaving two 



valves. 

 Capitate: Enlarged at tip. 

 Carina: Distinct median row of plates on aboral 



surface of arm. 

 Clavate: Club-shaped. 



SEA-STARS OF NORTH CAROLINA 



133 



