FISHERY BULLETIN: VOL. 80, NO. 4 



examination, reflected both spatial (microhabi- 

 tat) and seasonal differences in the littoral ich- 

 thyofauna (Fig. 6). 



Group I was a loosely associated group of the 

 five resident species (maintain populations year 

 round in littoral zone) which could be further di- 

 vided into three subgroups. Subgroup A had only 

 one member, Atherinops affinis, an abundant 

 schooling species. Clevelandia ios and Gillich- 

 thys mirabilis which comprised subgroup B are 

 burrow-inhabiting gobiids of the shallows and 

 pannes. Subgroup C included two species, Fun- 

 dulus parvipinnis and Gambusia affinis, which 

 inhabited pannes and other high intertidal 

 areas. Clevelandia ios, G. mirabilis, and F. par- 

 vipinnis are residents of salt marshes in Cali- 

 fornia and other west coast estuaries and are 

 probably the species most threatened by altera- 

 tions of these habitats. 



Group II consisted of three midwater school- 

 ing species— Anchoa compressa, A. delicatis- 

 sima, and Cymatogaster aggregata — most of 

 which were caught mainly from January to 

 August. 



Group III was made up of three distinctly sea- 

 sonal, benthic species: Two gobiids, Quietula 

 ycauda and Ilypnus gilberti, and a cottid, Lep- 

 tocottus armatus, which was relatively rare dur- 



ing 1978 compared with previous years (pers. 

 obs.). 



Group IV included an engraulid, Engraulis 

 mordax; syngnathids, Syngnathus spp. (includ- 

 ing S. auliscus and S. leptorhynchus); and the 

 pleuronectid, Hypsopsetta guttulata. These spe- 

 cies were seasonally present in mid- to late sum- 

 mer. Members of this group were only loosely 

 associated (> 80% distance). 



Group V was composed of four species which 

 were collected at times of low salinities. Lepomis 

 macrochirus and juveniles of Mugil eephalus 

 were sampled together early in the year (Janu- 

 ary-March 1978). Lepomis cyanellus and Leures- 

 thes tenuis were found together only in Septem- 

 ber. 



Group VI included 12 rare species, most of 

 which could be considered summer periodics in 

 the littoral zone in 1978. These were Umbrina 

 roncador, Urolophus halleri, Paralichthys cali- 

 fornicus, Mustelus californicus, Cynoscion nobil- 

 is, Acanthogobius flavimanus, Sphyraena argen- 

 tea, Girella nigricans, Symphurus atricauda, 

 Porichthys myriaster, Morone saxatilis, and 

 Seriphus politus. 



Members of the species groups identified in 

 the dendrogram (Fig. 6) are illustrated in dia- 



% DISTANCE 



140 



120 



100 



80 



_!_ 



60 



40 



_L_ 



20 



{1 



Q 



d 



Atherinops affinis 

 Clevelandia ios i 



Gillichthys mirabilis J 

 Fundulus parvipinnis l 

 Gambusia affinis J 



Anchoa delicatissima 

 Cymatogaster aggregata 

 Anchoa compressa 

 Quietula ycauda 

 Ilypnus gilberti 

 Leptocottus armatus 

 Engraulis mordax 

 Syngnathus spp. 

 Hypsopsetta guttulata 

 Mugil eephalus 

 Lepomis macrochirus 

 Lepomis cyanellus 

 Leuresthes tenuis 



}A 



III 



IV 



Figure 6.— Dendrogram of the clustering of littoral fish species by individual samples taken at stations 1-3 in 

 upper Newport Bay, five species groups (Roman numerals) are recognized according to the Bray-Curtis index 

 of dissimilarity (% distance). A, B, and C are subgroups of species Group I. 



778 



