Behavior Triggerfish

1 behavior

1.1 male territoriality
1.2 spawning , biparental care
1.3 mating systems

behavior

the titan triggerfish can move relatively large rocks when feeding , followed smaller fish, in case orange-lined triggerfish , moorish idol, feed on leftovers

the rather bizarre anatomy of triggerfishes reflects typical diet of slow-moving, bottom dwelling crustaceans, mollusks, sea urchins , other echinoderms, creatures protective shells , spines. many take small fishes , some, notably members of genus melichthys, feed on algae. few, example redtoothed triggerfish (odonus niger), feed on plankton. known exhibit level of intelligence unusual among fishes, , have ability learn previous experiences.

picasso triggerfish bite

some triggerfish species can quite aggressive when guarding eggs. both picasso (rhinecanthus aculeatus) , titan triggerfish (balistoides viridescens) viciously defend nests against intruders, including scuba divers , snorkelers. territory extends in cone nest toward surface, swimming upwards can put diver further fishes territory; horizontal swim away nest site best when confronted angry triggerfish. unlike relatively small picasso triggerfish, titan triggerfish poses serious threat inattentive divers due large size , powerful teeth.

male territoriality

triggerfish males migrate traditional spawning sites prior mating , establish territories. male species (i.e. balistes carolinensis , pseudobalistes flavimarginatus) build hollow nests within territories. triggerfish males fierce in guarding territories having territory essential reproduction. male s territory used spawning , parental care. male territories located on sandy sea bottom or on rocky reef. single territory includes more 1 female, , male mates of females residing in or visiting territory (polygyny). in hachijojima, izu islands, japan, 1 male crosshatch triggerfish (xanthichthys mento) has 3 females in territory @ same time, , mates them in pairs. each male red-toothed triggerfish (odonus niger) mates more ten females in territory on same day. yellow margin triggerfish (pseudobalistes flavimarginatus) exhibit polygyny mating.

spawning , biparental care

triggerfish spawning timed in relation lunar cycles, tides, , time of changeover of tides. in relation lunar cycles, eggs observed 2–6 days before full moon , 3–5 days before new moon. in relation tides, spawning happens 1–5 days before spring tide. in relation timing of tides, eggs observed on days when high tides take place around sunset.

male , female triggerfish perform pre-spawning behaviors: blowing , touching. male , female blow water on sandy bottom (usually in same spot @ same time) , set egg site. touch abdomens on bottom if spawning. during actual spawning, eggs laid on sandy sea bottom (triggerfish demersal spawners despite large size). eggs scattered , attached sand particles. triggerfish eggs small (diameter of 0.5-0.6mm) , spread waves. after spawning, both male , female participate in caring fertilized eggs (biparental egg care). female triggerfish stays near spawning ground, around 5 meters off bottom, , guards eggs within territory against intruders. common intruders include parupeneus multifasciatus, zanclus cornutus, prionurus scalprum , conspecifics. besides guarding, females roll, fan, , blow water on eggs provide oxygen embryo, thereby inducing hatching. behavior of female triggerfish called tending, , males perform behavior. male triggerfish stays farther above eggs , guards females , eggs in territory. males exhibit aggressive behaviors against conspecific males near boundaries of territories.

mating systems

in crosshatch triggerfish (xanthichthys mento) , yellow margin triggerfish (pseudobalistes flavimarginatus), eggs spawned in morning , hatch after sunset on same day. after hatching of embryos, female crosshatch triggerfish leaves male s territory. mating system example of male-territory-visiting polygamy. triggerfishes exhibit other types of mating systems, well, such nonterritorial-female (ntf) polygyny , territorial-female (tf) polygyny. in ntf polygyny, nonterritorial females stay in male s territory , reproduce. in tf polygyny, female owns territory within male s territory , spawn in territory.