BRAY and EBELING: THREE "PICKER-TYPE" FISHES 



larger mouth, the white seaperch may eat not only 

 small items, but also an array of items too large to 

 be ingested by the other two. 



Other studies indicate that white seaperch 

 forage opportunistically in a relatively broad 

 range of kelp-bed and adjacent habitats. Although 

 plant-encrusting bryozoans were by far their 

 major food in the Santa Barbara areas of kelp and 

 reef, they were of minor importance in fish 

 collected off San Diego. Quast (1968b) reported 

 that 18 fish from a kelp bed contained mostly small 

 crustaceans, worms, and bivalves, while Hobson 

 (1971) noted that 5 fish from shallow areas of surf 

 grass contained small crustaceans, especially 

 caprellid amphipods. DeMartini (1969) concluded 

 that the white seaperch is almost "cosmopolitan" 

 among habitats, including bays and artifacts far 

 from the kelp beds. He observed that, unlike the 

 kelp perch, it has uniformly broad and densely set 

 pharyngeal teeth and commonly eats large, hard- 

 shelled items like barnacles and clams. 



Although the kelp perch and senorita have 

 superficially similar feeding mechanisms, they do 

 not overlap broadly in their diets. Off Santa Bar- 

 bara, in fact, food overlap is least between senorita 

 and kelp perch and greatest between senorita and 

 white seaperch, whose mouth structure and denti- 

 tion are more generalized. These relations prevail 

 because the kelp perch does not eat substantial 

 amounts of the plant-encrusting bryozoans, the 

 overwhelmingly predominate food item of the 

 other two. Disregarding bryozoans, the remaining 

 (minor) food array of the senorita actually resem- 

 bles more closely that of the kelp perch than that 

 of the white seaperch. Likewise, off San Diego, 

 kelp perch favor copepods and gammarid 

 amphipods (Quast 1968b), and senoritas favor 

 bryozoans (Quast 1968b; Hobson 1971) but may 

 eat a variety of small crustaceans associated with 

 giant kelp as well (Limbaugh 1955). 



Because food overlap between the two cleaners 

 is effectively small, they may co-occur with 

 minimal mutual interference, even though their 

 habitat overlap in the upper kelp bed is relatively 

 broad. Also, their daytime activity patterns differ 

 noticeably. Whereas kelp perch dart sporadically 

 among the kelp blades and seem to feed almost 

 continuously, senoritas move continuously about 

 in open water as well as in dense kelp and seem to 

 feed more sporadically. Also, solitary kelp perch 

 continue their rapid picking about well past mid- 

 afternoon after senoritas were observed to curtail 

 their feeding activity. 



It would seem that the senorita and white 

 seaperch are greater potential competitors 

 because they overlap almost completely in both 

 food and habitat within the kelp-bed area. But 

 even so, it is doubtful that availability of their 

 principal food, bryozoans, is a limiting factor in 

 the Santa Barbara area, where encrustations are 

 widespread over the kelp and other substrates. 

 Furthermore, the frequency of occurrence of 

 white seaperch within the kelp bed is quite low 

 compared to that of the senorita. Even though 

 fairly large aggregations are seen occasionally 

 over the reef, the center of abundance of white 

 seaperch may be in more peripheral areas where 

 alternative prey are readily available. 



The senorita, which belongs to the large tropical 

 family of wrasses, is more specialized in diel 

 behavior than are the kelp perch and white 

 seaperch. Whereas at night the perches simply 

 slow down and become less responsive, the senori- 

 ta buries itself in pockets of sand or gravel on the 

 reef. Wrasses in general are strickly diurnal: 

 they seek cover and become quiescent at night, as 

 has been observed for tropical species (Hobson 

 1965, 1968, 1972, 1974; Stark and Davis 1966; 

 Collette and Talbot 1972; Smith and Tyler 1972) 

 and for other temperate species (Chao 1973; 011a et 

 al. 1975). Various species hide in holes, bury them- 

 selves, and/or protect themselves with mucus en- 

 velopes (Hobson 1965, etc.). In the tropics, they are 

 among the first fishes to take cover at dusk and the 

 last to emerge at dawn, a practice that may 

 minimize their vulnerability during the crepus- 

 cular hours when predation is most intense (Hob- 

 son 1968, 1972; Collette and Talbot 1972). In the 

 kelp beds of the temperate zone, there may be 

 relatively few nocturnal piscivores as compared 

 with the tropics. Thus, the senorita may retain the 

 burying habit of its family (which implies a 

 complex genetic basis) simply because there are no 

 pressures actively selecting against this trait (cf . 

 Hobson 1972). 



Many tropical "pickers" have elongated snouts 

 and small mouths with projecting teeth for select- 

 ing and removing tiny prey from otherwise inac- 

 cessible places (Alexander 1967; Hobson 1968, 

 1974). These are also adaptations for picking ec- 

 toparasites from larger fishes, and indeed many of 

 the small and sharp-nosed tropical-reef fishes are 

 part-time or "facultative" cleaners (Hobson 1971, 

 1974; Losey 1972). Likewise, the tendency of kelp 

 perch and senoritas to clean may vary among sit- 

 uations or individuals (Hobson 1971) and may 



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