The Labrid Genus,Cirrhilabrus Temminck and Schlegel,Is Represented by Nine Nominal Species Occuring from Africa and the Red
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Japanese Journal of Ichthyology 魚 類 学 雑 誌 Vol.22,No.11975 22巻1号1975年 Notes on the Spawning Behavior of the returning to their original position.On one occa- Wrasse,Cirrhilabrus temminckii sion,a clearly visible cloud of reproductive materi- als was snapped out at the apex of the upward Jack T.Moyer and John W.Shepard dash.Once,a drably colored individual left the Received October 8,1974)( male and swam downward toward the other members of the aggregate.He chased after it,his The labrid genus,Cirrhilabrus Temminck and bright iridescent caudal fin churning rapidly,as it Schlegel,is represented by nine nominal species had in the looping signal display. occuring from Africa and the Red Sea east to Although spawning has been observed only on Hawaii and north to Japan( de Beaufort,1940; the above occasion,we have frequently seen Shultz,1960;Springer and Randall,1974).Breder variations of the courtship display.These always and Rosen(1966)make no mention of the spawn- consisted of a single brightly colored male with an ing and reproductive behavior of any species of the aggregate of drably colored individuals.The male constantly moved around throughout the genus in their book of fish reproduction and we have found little reference to it elsewhere. group,feeding and occasionally enticing.His At approximately 4:45 PM,Aug.24,1974,we body color,at depths of from 7,-14 m,appeared lavender,and his caudal fin,anal fin,and soft observed the spawning of the wrasse,Cirrhilabrus rays of the dorsal fin were always an iridescent temminckii Bleeker,in 7 m waters in Igaya Bay, light blue,visible from a great distance,but less Miyake Island,Japan(34•‹05'N,139•‹30'E).The brilliant than during spawning.In one frequently substrate at the spawning site consisted of small, observed individual,the soft rays of the dorsal algae covered rocks over sand,with extensive fin moved rapidly at all times,even as he fed,as outcroppings of coral within five meters of the if to flash his presence to all in the aggregate. site.Reproductive activity was centered around Caudal and anal fins were not extended and did a relatively large boulder near the center of the not move.Feeding males in other aggregates site.The water temperature was 25•‹C. did not flash their soft dorsal or any other fin.In We were attracted to the spawning site by the all cases,the long and narrow pelvic fins were conspicuous signaling behavior of the male.His extended downward,white,and clearly visible. entire body appeared to be a deep iridescent blue, Enticement began with the entire body turning except for the anal fin,caudal fin,and the soft a deep iridescent blue,but less brilliant than in dorsal fin,all of which were light,shiny iridescent the spawning individual.The caudal,anal,and blue and the pelvic fins which were white.He soft dorsal fins remained very light and iridescent. circled rapidly in a counterclockwise direction Enticement was usually accompanied by extreme- from a point about 1.5 m upwards to about 3m above the substrate.His caudal fin flashed in ly rapid movement of the soft dorsal,caudal,and rapid movement,its shiny iridescence visible hori- possibly the anal fin.However,in some indi- viduals,only the caudal fin was flashed,with zontally for perhaps 15 m.Ten or more drably the soft dorsal folded against the body.Often, colored C.temminckii aggregated around the the male initially chased a drably colored fish as boulder at heights varying from a few centimeters if to attract its attention;later going into the to 1 m above the substrate.The rapid looping looping display described above.The long pelvic display seemed to attract their attention and the fins were extended throughout all phases of entire aggregate gradually moved nearer to the courtship. male.On four occasions,a single member of the aggregate,but not always the same one,rose higher Courtship displays have been observed at than the others.Each time,the male rushed to a depths of from 7,-14 m,in water temperatures point very close to the approaching individual, from 21•Ž•`28•Ž,morning and afternoon,and perhaps even touching it with his side or abdomen. at all phases of the moon.Our earliest court- Then,both fish dashed in a sharp upward angle ship observation was on May 13,1974 and the from the boulder to a point more than 3 m above latest on Aug.25,1974. the substrate,suddenly reversing direction and ―40― Moyer and Shepard:Spawning Behavior of the Wrasse individual observed.A feeding individual is Discussion less brilliant than an enticing individual,which in turn is less brilliant than a spawning fish.How- The upward spawning rush,followed by the snapping downward motion as gametes are ever,the bright phase specimen is easily distin- released,appears very similar to spawning behav- guished from the drab members of the aggregate at all times. ior of various wrasses of the genera Thalassoma Swainson(Breder and Rosen,1966;Feddern, Although systematic collection and gonadal 1965;Hobson,1965;Moyer,1974;Randall and examination were not conducted,we assume that Randall,1963),Stethojulis Giinther(Shepard and the bright phase C.temminckii is a dominant, Meyer,personal observation),Halichores(Randall sexually active male and the drab individuals and Randall,1963),and Coris(personal observa- are immatures,females,and possibly sexually tion).Further similarities are apparent between inactive males.Such a trend has been reported the reproductive behavior of C.temminckii and in other labrids exhibiting either full or developed the paired spawning activity of Thalassoma bifascia- dichromatism(Choat,1969;Reinboth,1973). tum® T.bifasciatum males participating in paired A close look at drab members in C.temminckii spawning are invariably bright phase individuals. aggregates shows interesting variations in color As in C.temminckii,paired spawning is initiated and morphology.The largest individuals often from a prominent point of visual reference, have lost the white spot on the snout and some e.g.,an outcropping of elkhorn coral(Reinboth, have lavender coloring along the lateral line. 1973).Males exhibit a spiralling upward move- In a few,the soft dorsal and caudal fins are ment,with a quivering motion of the caudal fin, turning blue.In many large specimens,the pelvic immediately prior to the spawning dash. fins are somewhat elongated and backs are slightly Group spawning has not been observed in humped,but not nearly as marked as in bright C.temminckii,but does occur in Stethojulis individuals.Large specimens of this type equal (Shepard and Meyer,personal observation)and bright individuals in size.The role of these is common in Thalassoma(Feddern,1965; transitional specimens is of special interest.The Randall and Randall,1963).Randall(personal presence of a single bright phase individual in communication)suggests that many wrasse genera each group,and the morphological and color exhibit both paired and group spawning,although variations of the drab individuals described above, one form or the other may predominate to the may suggest a social sex reversal similar to that extent of seeming to be the sole method of of Labroides dimidiatus(Valenciennes)(Robertson, reproduction if field observations have been 1972).A struggle for dominance,perhaps related limited or incomplete.The possibility must be to sex reversal,may have been the motivation for considered that observations made under different aggressive behavior observed on Sept.15,1974. ecological conditions or in other geographical A transitional C.temminckii,with lavender lateral areas would reveal group spawning in this species. line coloring and blue soft dorsal and caudal fins, In C.temminckii two basic color phases are was observed aggressively pursuing a similarly observed:a"drab"phase and a developed or colored individual.The chase continued for per- "bright"phase.The latte r is rare,occuring haps 15 seconds,in and around the aggregate of only in a single large individual in a given aggre- 10,12 fish.Suddenly,the pursued fish turned gate.The drab phase is the common form,being on it's aggressor and instantly the two fish locked observed in individuals of all sizes.C.temminckii jaws.They held this pose,completely motionless seems to exhibit"developed dichromatism",as for about 6e7 sec.,then turned abruptly in described by Choat(1969);the colors of the opposite directions and resumed feeding. bright phase C.temminckii represent an intensi- However,the possbility of a social hierarchy fication of the drab coloration.On the other hand among the male members of a C.temminckii ag- full dichromatism which shows a distinctly unique gregate cannot be discounted.In Thalassoma pattern is found in Thalassoma bifasciatum(see bifasciatum,a single dominant male commands a Stoll,1955).The intensity of the bright phase given spawning site,suppressing the sexual activity seems to vary according to the activity of the of the lower ranking males in the surrounding area ―41― 魚 類 学 雑 誌Japan.J.Ichthyol.22(1),1975 (Reinboth,1973).It is possible that the transition fish, Sparisoma rubipinne; with notes on other of a drab male C.temminckii to the bright phase, scarid and labrid fishes. Zoologica, 48 (2): 49•`60, and thus his sexual activity,is controlled by the 2 figs, 2 pls. presence of a bright individual in an aggregate. Reinboth, R. 1973. Dualistic reproductive behavior Further studies of the behavior and reproductive in the protogynous wrasse Thalassoma bifasciatum and some observations on its day-night change- physiology of this species,particularly the sexual identities of the color phases,are needed. over. Helgolander Wiss.