Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Triggerfish
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
==Behavior== The anatomy of the triggerfish reflects its typical diet of slow-moving, bottom-dwelling [[crustacea]]ns, [[mollusk]]s, [[sea urchins]] and other [[echinoderm]]s, generally creatures with protective shells and spines. Many will also take small fishes and some, notably the members of the genus ''[[Melichthys]]'', feed on [[algae]].<ref name=Lieske/> A few, for example the [[redtoothed triggerfish]] (''Odonus niger''), mainly feed on [[plankton]].<ref name=Lieske/> They are known to exhibit a high level of [[Fish intelligence|intelligence for a fish]], and have the ability to learn from previous experiences.<ref name=McDavid/><ref name="Debelius">{{Cite book|title=Indian Ocean Tropical Fish Guide|last=Debelius|first=Helmut|publisher=Aquaprint Verlags GmbH|year=1993|isbn=3-927991-01-5}}</ref> Some triggerfish species can be quite aggressive when guarding their eggs. Both the [[Lagoon triggerfish|Picasso]] (''Rhinecanthus aculeatus'') and [[titan triggerfish]] (''Balistoides viridescens'') viciously defend their nests against intruders, including scuba divers and snorkelers. Their territory extends in a cone from the nest toward the surface, so swimming upwards can put a diver further into the fishes' territory; a horizontal swim away from the nest site is best when confronted by an angry triggerfish. Unlike the relatively small Picasso triggerfish, the titan triggerfish poses a serious threat to inattentive divers due to its large size and powerful teeth.<ref name="Millington">{{cite journal|last1=Randall|first1=J.E.|author-link=John Ernest Randall|last2=Millington|first2=J.T.|year=1990|title=Triggerfish bite – a little-known Marine hazard|journal=Journal of Wilderness Medicine|volume=1|issue=2|pages=79–85|doi=10.1580/0953-9859-1.2.79}}</ref> ===Male territoriality=== Triggerfish males migrate to their traditional spawning sites prior to mating and establish territories. Some male species (i.e.'' [[Balistes carolinensis]]'' and ''[[Pseudobalistes flavimarginatus]]'') build hollow nests within their territories.<ref>{{cite journal|last1=Lobel|first1=Philip S.|last2=Johannes|first2=Robert E.|date=September 1980|title=Nesting, egg and larvae of triggerfish (Balistidae).|journal=[[Environmental Biology of Fishes]]|volume=5|issue=3|pages=251–252|doi=10.1007/bf00005359|bibcode=1980EnvBF...5..251L |s2cid=3213367}}</ref> Triggerfish males are fierce in guarding their territories as having a territory is essential for reproduction. A male's territory is used for spawning and parental care. Most male territories are located over a sandy sea bottom or on a rocky reef. A single territory usually includes more than one female, and the male mates with all of the females residing in or visiting his territory ([[Polygyny in animals|polygyny]]). In Hachijojima, [[Izu Islands]], Japan, one male crosshatch triggerfish (''[[Xanthichthys mento]]'') has up to three females in his territory at the same time, and mates with them in pairs. Each male red-toothed triggerfish (''[[Odonus niger]]'') mates with more than 10 females in his territory on the same day.<ref name=":6">{{cite journal|last=Kawase|first=Hiroshi|date=March 2003|title=Spawning behavior and biparental egg care of the crosshatch triggerfish, ''Xanthichthys mento'' (Balistidae).|journal=[[Environmental Biology of Fishes]]|volume=66|issue=3|pages=211–219|doi=10.1023/a:1023978722744|bibcode=2003EnvBF..66..211K |s2cid=35997227}}</ref> Yellow margin triggerfish (''[[Pseudobalistes flavimarginatus]]'') also exhibit polygyny. ===Spawning and biparental care=== Triggerfish spawning is timed in relation to lunar cycles, tides, and time of changeover of tides. In relation to lunar cycles, eggs are observed 2–6 days before the full moon and 3–5 days before the new moon. In relation to tides, spawning happens 1–5 days before the spring tide. In relation to timing of tides, eggs are observed on days when high tides take place around sunset.<ref name=":7">{{cite journal|last=Gladstone|first=William|date=March 1994|title=Lek-like spawning, parental care and mating periodicity of the triggerfish ''Pseudobalistes flavimarginatus'' (Balistidae).|journal=[[Environmental Biology of Fishes]]|volume=39|issue=3|pages=249–257|doi=10.1007/bf00005127|bibcode=1994EnvBF..39..249G |s2cid=36747250}}</ref> [[File:Titan Triggerfish.jpg|thumb|360px| The [[titan triggerfish]] can move relatively large rocks when feeding and is often followed by smaller fish, in this case [[orange-lined triggerfish]] and [[moorish idol]], that feed on leftovers.]] Male and female triggerfish perform certain prespawning behaviors: blowing and touching.<ref name=":6" /> A male and female blow water on the sandy bottom (usually in the same spot at the same time) and set up their egg site. They touch their abdomens on the bottom as if they are spawning. During actual spawning, eggs are laid on the sandy sea bottom (triggerfish are [[Demersal fish|demersal]] spawners despite their large size). Eggs are scattered and attached to sand particles. Triggerfish eggs are usually very small (diameter of 0.5–0.6 mm)<ref name=":7" /><ref>{{cite journal|last=Kawase|first=Hiroshi|year=2003|title=Maternal egg care in the bridled triggerfish, ''Sufflamen fraenatus'' (Balistidae) at Hachijojima island, Japan.|journal=Natural History Research|volume=7|pages=193–197}}</ref> and are easily spread by waves. After spawning, both the male and female participate in caring for the fertilized eggs (biparental egg care). A female triggerfish stays near the spawning ground, around 5 m off the bottom, and guards the eggs within her territory against intruders. Some common intruders include ''[[Parupeneus multifasciatus]], [[Zanclus cornutus]], [[Prionurus scalprum]]'', and conspecifics. Besides guarding, females roll, fan, and blow water on eggs to provide oxygen to the embryos, thereby inducing hatching.<ref>{{cite web|url=http://www.howfishbehave.ca/pdf/Are%20fishes%20good%20parents.pdf|title=Are fishes good parents?|last=Reebs|first=Stéphan G.|date=2011–2015|publisher=[[Université de Moncton]]|via=howfishbehave.ca|url-status=live|archive-url=https://web.archive.org/web/20160304031133/http://www.howfishbehave.ca/pdf/Are%20fishes%20good%20parents.pdf|archive-date=4 March 2016}}</ref> This behavior of female triggerfish is called "tending", and males rarely perform this behavior. A male triggerfish stays farther above the eggs and guards all the females and eggs in his territory. Males exhibit aggressive behaviors against conspecific males near the boundaries of their territories. ===Mating systems=== In crosshatch triggerfish (''[[Xanthichthys mento]]'') and yellow margin triggerfish (''[[Pseudobalistes flavimarginatus]]''), eggs are spawned in the morning and they hatch after the sunset on the same day. After hatching of embryos, the female crosshatch triggerfish leaves the male's territory. This mating system is an example of male-territory-visiting [[Animal sexual behaviour#Polygamy|polygamy]]. Triggerfishes exhibit other types of mating systems, as well, such as a nonterritorial-female (NTF) polygyny and territorial-female (TF) polygyny. In NTF polygyny, nonterritorial females stay in the male's territory and reproduce. In TF polygyny, a female owns territory within a male's territory and will spawn in her territory.<ref name=":6" />
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)