Development and Distribution of Larvae and Pelagic 



Juveniles of Three Kyphosid Fishes {Girella nigricans, 



Medialuna californiensis, and Hermosilla azurea) off 



California and Baja California 



Elizabeth G. Stevens, William Watson, and H. Geoffrey Moser 



ABSTRACT: Complete developmental series are 

 described for larvae and pelagic juveniles of three 

 kyphosid fishes, Girella nigricans (Ayres), Me- 

 dialuna californiensis (Steindachner), and Her- 

 mosilla azurea (Jenkins and Evermann), from Cali- 

 fornia and Baja California coastal waters. Larvae 

 of the three species have a similar compact body 

 form, with G. nigricans being the most slender and 

 H. azurea the most robust. They share a number of 

 pigment characters: including dorsal, ventral, and 

 lateral midline melanophore series; an embedded 

 melanistic band through the eye region; and minute 

 melanophores at the tip of the notochord. Unique 

 pigment variations permit the identification of all 

 developmental stages of these species. Each has a 

 specialized pelagic juvenile stage with distinct pig- 

 mentation. The pelagic distribution of each species 

 is described; larvae ofM. californiensis are the most 

 oceanic and those of H. azurea the most coastal of 

 the three species. The ontogenetic characters of 

 these species are consistent with the view that they 

 are monophyletic. 



The opaleye, Girella nigricans, occurs from San 

 Francisco, California, to Cabo San Lucas, Baja 

 California. It is a prominent member of near- 

 shore rocky reef and kelp communities from 

 southern California to central Baja California 

 and ranges from the intertidal zone to about 30 m 

 depth. The halfmoon, Medialuna californiensis, 

 occurs from Vancouver Island, Canada, to the 

 Gulf of California, but is rare north of Point Con- 

 ception, CaUfornia. Its preferred habitat is sim- 

 ilar to that of G. )ngricans, although it ranges 

 deeper to 40 m. The zebra perch, Hermosilla 



Elizabeth G. Stevens, Southwest Fisheries Center La Jolla 

 Laboratory, National Marine Fisheries Service, NOAA, 

 P.O. Box 271, La Jolla, CA 92038. 



William Watson, MEC Analytical Systems, Inc., 2433 

 Impala Drive, Carlsbad. CA 92009: present address: South- 

 west Fisheries Center La Jolla Laboratory, National Marine 

 Fisheries Service, NOAA, P.O. Box 271, La Jolla, CA 92038. 

 H. Geoffrey Moser, Southwest Fisheries Center La Jolla 

 Laboratory, National Marine Fisheries Service, NOAA, 

 P.O. Bo.x 271. La Jolla, CA 92038. 



azurea, is known from Monterey Bay, Cali- 

 fornia, to the Gulf of California but prefers 

 warmer waters and is rare north of southern 

 Cahfornia. It is found in shallow inshore areas to 

 a maximum depth of 8 m (Miller and Lea 1972; 

 Feder et al. 1974; Eschmeyer et al. 1983). 



Opaleye and halfmoon are part of the inci- 

 dental catch of the coastal purse seine fleet and 

 are sold as "perch" in the fresh fish market 

 (Fitch and Lavenberg 1971). Annual landings of 

 opaleye average about 2V2 tons with a maximum 

 of 12 tons in 1973; halfmoon landings average 

 about 7 tons annually with a maximum of 25 

 tons in 1968 (Heimann and Carlisle 1970; 

 McAllister 1975). Halfmoon are seasonally 

 abundant in the southern California commercial 

 passenger fishing boat catch, ranking as high as 

 fifth in numbers caught (Crook 1978). They also 

 consistently rank among the top 10 species 

 caught by the southern California private sport 

 fishery (Wine 1982). Fewer opaleye are landed 

 in these fisheries, reflecting the shallower dis- 

 tribution of this species; however, opaleye are a 

 mainstay for rocky-shore anglers in southern 

 Cahfornia and are the second most important 

 species in competitive spearfishing events 

 (Pinkas et al. 1968; Fitch and Lavenberg 1971). 

 Zebra perch are taken occasionally by southern 

 California shore anglers and spearfishers (Lim- 

 baugh 1955; Feder et al. 1974). 



Knowledge of the early hfe histories of opaleye 

 and halfmoon is scanty. They spawn during 

 spring and summer and their larvae appear in 

 nearshore plankton tows during this period. 

 Both species have a silvery pelagic juvenile 

 stage, and both appear in small schools in near- 

 shore areas and around floating masses of kelp. 

 Halfmoon continue their juvenile development in 

 these habitats, whereas opaleye enter tidepools 

 at about 25 mm length and change abruptly to 

 olive colored individuals which have one or two 

 white spots on the back, lateral to the dorsal fin. 

 They remain in the intertidal region until about 



Manuscript Accepted May 1989. 

 Fishery Bulletin, U.S. 8?": 745-768. 



745 



