LIFE HISTORY, ECOLOGY, AND BEHAVIOR OF 



LIPARIS INQUILINUS (PISCES: CYCLOPTERIDAE) ASSOCIATED 



WITH THE SEA SCALLOP, PLACOPECTEN MAGELLANICUS' 



K. W. Able^ and J. A. MusiCK^ 



ABSTRACT 



In the Mid-Atlantic Bight, spawning ofLiparis inquilinus peaked near shore, away from sea scallop 

 beds, in March and April. In the laboratory, females appeared to initiate spawning activity and each 

 female probably spawned more than once. The eggs are adhesive and demersal and have been found 

 attached to hydroids in nature. The larvae were most abundant in plankton collections inshore in May 

 and averaged 5 mm total length at that time. Larger larvae were found in deeper water, and by 12-13 

 mm total length they had undergone metamorphosis and descended to the bottom where they became 

 associated with the sea scallop, Placopecten magellanicus. They maintained this association from 

 August through December. The population comprises a single year class which leaves the scallops and 

 migrates inshore to spawn as the fish are entering their second year. 



Laboratory and field observations indicated that fish were more abundant in the scallops and more 

 scallops contained fish during the day. At night, fish left the scallops to feed on small crustaceans. 

 Liparis inquilinus observed in aquaria used the fin rays of the lower lobe of the pectoral fin to detect 

 food. These fin rays have taste buds on the surface of each ray. 



Liparis inquilinus is probably protected from predation while inside sea scallops since there are few 

 predators on the scallops of the size usually occupied. Predation while outside the scallop may be 

 minimized by feeding only at night and then returning as soon as the fish becomes satiated. Sea scallops 

 seem to suffer no ill effects from the association and they do not compete for food with L. inquilin us since 

 P. magellanicus is a microplanktonic filter feeder and the former feeds on small crustaceans. 



Little is known of the life history of most species 

 of L/paWs. Most of the meager information avail- 

 able for North Atlantic Liparis is included in 

 Bigelow and Schroeder (1953), Andriyashev 

 (1954), Leim and Scott (1966), and Wheeler 

 (1969). Unfortunately, taxonomic problems re- 

 main and some published life history information 

 may be incorrect because of misidentification. Re- 

 cently, Detwyler (1963) studied the life history 

 and reproductive biology of L. atlanticus from 

 New Hampshire and Maine, and Able (in press) 

 commented on the life history of a new species of 

 Liparis from the Gulf of Maine. Elsewhere, 

 Nizortsev et al. (1963) noted the stomach contents 

 of L. koefoedi, L. liparis, and L. lapteui in the Ba- 

 rents Sea; Johnson (1969, 1970) reported on food 

 habits and age and growth of L. pulchellus off 

 California; Kosaka (1971) described the food 

 habits and seasonal distribution of L. tanakae 

 from Japan; Gibson (1972) mentioned the vertical 



'Contribution No. 730 from the Virginia Institute of Marine 

 Science. 



^Biology Department, McGill University, Montreal, Quebec, 

 Canada. 



^Virginia Institute of Marine Science, Gloucester Point, VA 

 23062. 



distribution and feeding of L. montagui; and 

 Quast (1968) described the food habits of L. 

 mucosas off California. 



The association between Lipam (= L. inquili- 

 nus, see Able 1973) and the sea scallop, Placopec- 

 ten magellanicus, has been reported by several 

 authors (Bean 1884; Goode 1884; Garman 1892; 

 Goode and Bean 1895; Jordan and Evermann 1898; 

 Welsh 1915; Burke 1930; Bigelow and Schroeder 

 1953; Leim and Scott 1966) but information is lack- 

 ing on most aspects of the assocation. The purpose 

 of this paper is to report on the life history, ecology, 

 and behavior of L. inquilinus. 



MATERIALS AND METHODS 



The life history stages, although often overlap- 

 ping, are defined as follows: larvae — planktonic 

 individuals usually 3-13 mm total length (TL), 

 which have not transformed to adult coloration; 

 juveniles — sexually immature benthic individu- 

 als with adult coloration, often associated with 

 the sea scallop, approximately 14-45 mm TL; and 

 adults — sexually mature individuals greater 

 than 33 mm TL. The latter can be distinguished 

 by the presence of prickles on the body of males 



Manuscript accepted December 1975. 

 FISHERY BULLETIN: VOL. 74, NO, 2. 1976. 



409 



