Editing Dragonet

{{Short description|Family of fishes}}
{{for|the fictional dragonet of Pern|fire-lizard}}
{{Automatic taxobox
| name = Dragonets
| image = ocellated dragonet.jpg
| image_caption = Ocellated dragonet, ''[[Synchiropus ocellatus]]''
| taxon = Callionymidae
| authority = [[Charles Lucien Bonaparte|Bonaparte]], 1831
| subdivision_ranks = Genera
| subdivision = See text
| type_species = ''[[Callionymus lyra]]''
| type_species_authority = [[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]]
}}

'''Dragonets''' are small [[Percomorpha|percomorph]] marine [[fish]] of the diverse family '''Callionymidae''' (from the [[Greek language|Greek]] ''kallis'', "beautiful" and ''{{Transliteration|el|onyma}}'', "name") found mainly in the tropical waters of the western [[Indo-Pacific]]. They are [[Benthos|benthic]] organisms, spending most of their time near the sandy bottoms, at a depth of roughly two hundred meters. There exist 139 [[species]] of the fish, in nineteen [[genera]].

Due to similarities in [[Morphology (biology)|morphology]] and behavior, dragonets are sometimes confused with members of the [[goby]] family. However, male dragonets can be differentiated from the goby by their very long dorsal fins, and females by their protruding lower jaws. The [[Draconettidae]] may be considered a sister family, whose members are very much alike, though rarely seen.

==Genera==
The following genera are classified within the Callionymidae:<ref name=FishBase>{{FishBase family | family = Callionymidae| month = August | year = 2019}}</ref>

* ''[[Anaora]]'' <small>[[John Edward Gray|J. E. Gray]], 1835</small> 
* ''[[Bathycallionymus]]'' <small>[[Tesuji Nakabo|Nakabo]], 1982</small>
* ''[[Callionymus]]'' <small>[[Carolus Linnaeus|Linnaeus]], 1758</small> (including ''[[Calliurichthys]]'')
* ''[[Diplogrammus]]'' <small>[[Theodore Nicholas Gill|Gill]], 1865</small> (including ''Chalinops'')
* ''[[Draculo]]'' <small>[[John Otterbein Snyder|Snyder]], 1911</small>
* ''[[Eleutherochir]]'' <small>[[Pieter Bleeker|Bleeker]], 1879</small>
* ''[[Eocallionymus]]'' <small>Nakabo, 1982</small>
* ''[[Foetorepus]]'' <small>[[Gilbert Percy Whitley|Whitley]], 1931</small>
* ''[[Neosynchiropus]]'' <small>[[Teodor T. Nalbant|Nalbant]], 1979</small>
* ''[[Paracallionymus]]'' <small>[[Keppel Harcourt Barnard|Barnard]], 1927</small>
* ''[[Protogrammus]]'' <small>[[Ronald Fricke|Fricke]], 1985</small>
* ''[[Pseudocalliurichthys]]'' <small>Nakabo, 1982</small>
* ''[[Repomucenus]]'' <small>Whitley, 1931</small>
* ''[[Spinicapitichthys spiniceps|Spinicapitichthys]]'' <small>Fricke, 1980</small>
* ''[[Synchiropus]]'' <small>Gill, 1859</small>
* ''[[Tonlesapia]]'' <small>[[Hiroyuki Motomura|Motomura]] & [[Takahiko Mukai|Mukai]], 2006</small>

==Description==
These "little [[european dragon|dragon]]s" are generally very colorful and possess cryptic patterns. Their bodies are elongated and scaleless. A large preopercular spine is characteristic of this fish,<ref name=FishBase/> and has been reported to be [[venom (poison)|venomous]] in some species. All fins are large, showy and elongated; the first high dorsal fin usually has four spines; in males, the first of these spines may be further adorned with filamentous extensions. Dragonets have flattened, triangular heads with large mouths and eyes; their tail fins are fan-shaped and tapered.

The largest species, the [[longtail dragonet]] (''Callionymus gardineri'') reaches a length of {{convert|30|cm|in}}. At the other end of the spectrum, the [[Saint Helena dragonet]] (''Callionymus sanctaehelenae'') reaches a length of just {{convert|2|cm|in}}. Many species exhibit marked [[sexual dimorphism]]: males and females are coloured and patterned differently from each other, and (in addition to the spine filament) males have a much higher dorsal fin. This difference is extreme in the [[high-finned dragonet]] (''Synchiropus rameus'').

==Reproduction==

Dragonet [[spawn (biology)|spawning]] occurs during late afternoons, right before the sun sets.<ref name=Spawning>{{cite journal|last=Takita|first=Toru|author2=Eiji Okamoto|title=Spawning behavior of the two dragonets, ''Callionymus flagris'' and ''C. richardsoni'', in the aquarium|journal=Japanese Journal of Ichthyology|date=22 March 1979|volume=26|issue=3|pages=282–288}}</ref> The fish's spawning behavior is divided into four distinctive stages: [[courtship display]], pairing, ascending, and the release of eggs and [[milt]].<ref name=Spawning/> Both male and female dragonets have been observed displaying and courting each other, although the practice is much more frequent in the males. Females only do so when they are ready to spawn and are in need of a mate.<ref name=Laboratory>{{cite journal|last=Gonzales|first=Benjamin J.|author2=Osamu Okamura |author3=Nobuhiko Taniguchi |title=Spawning behavior of laboratory-reared dragonet, ''Repomucenus huguenini'', and development of its eggs and prolarvae|journal=Aquaculture Science|year=1996|volume=44|issue=1|pages=7–15}}</ref> Both sexes display by spreading their [[Pectoral fin|pectoral]] and [[Caudal fin|caudal]] fins, and moving around or by the side of the other sex. Males will sometimes also spread their [[Dorsum (anatomy)|dorsal]] fins, repeatedly open and close their mouths, and position themselves on top of the females and rub their abdomens with their bodies. If a female accepts a male for spawning, they form a pair. Occasionally, another male might intrude upon the pair as they are mating and attempt to sneak fertilizations with the female. Such an act would result in aggression by the original male.<ref name=Breeding>{{cite journal|last=Awata|first=Satoshi|author2=Kimura, Motoko R. |author3=Sato, Noriyosi |author4=Sakai, Keita |author5=Abe, Takuzo |author6= Munehara, Hiroyuki |title=Breeding season, spawning time, and description of spawning behaviour in the Japanese ornate dragonet, ''Callionymus ornatipinnis'': a preliminary field study at the northern limit of its range|journal=Ichthyological Research|date=3 July 2009|volume=57|issue=1|pages=16–23|doi=10.1007/s10228-009-0116-z|s2cid=44243201 }}</ref>

Prior to spawning, a male and female dragonet pair will ascend approximately 0.7-1.2 meters up a [[water column]] from the sand at the bottom of the ocean.<ref name=Maturation>{{cite journal|last=Takita|first=Toru|author2=Teruyuki Iwamoto |author3=Shuya Kai |author4=Ichiro Sogabe |title=Maturation and spawning of the dragonet, ''Callionymus enneactis'', in an aquarium|journal=Japanese Journal of Ichthyology|year=1983|volume=30|issue=3|pages=221–226}}</ref> The male assumes a parallel position to the female, touching the female's side with the part of its body near its [[ventral]] fin.<ref name=Maturation/> The pair rises slowly up the water column, moving in a semicircular manner by swimming with their pectoral fins.<ref name=Maturation/> The ascent occurs in two phases. During the first phase, the dragonet pair moves upward about fifteen centimeters and rests for around five seconds.<ref name=Maturation/> Then it proceeds with its second rise. During this second phase of the ascent, the male and female flex their bodies and move their [[genital papilla]]e toward each other.<ref name=Maturation/> The male releases its ejaculate and the female releases its eggs. The release of eggs occurs singly and continuously for approximately five seconds.<ref name=Maturation/> The eggs are [[pelagic]], floating freely in the water column.<ref name=Maturation/> The female releases a high number of eggs during each spawning, and the dragonets do not guard their offspring.<ref name=Maturation/> The eggs are buoyant, so they intermingle with plankton and get swept away by the ocean current.<ref name=Maturation/> After the spawning, the dragonet pair parts from each other and swims back down to the ocean floor. Male dragonets are [[polygynous]], and will begin to search for other females to repeat the mating process with.<ref name=Maturation/> They generally spawn with several different females within one reproductive day. Dragonets are very sexually dimorphic, with the males being much larger and having longer fins than the females.<ref name=Tosa>{{cite journal|last=Gonzales|first=Benjamin J.|author2=Nobuhiko Taniguchi |author3=Osamu Okamura |title=Spawning cycle of two dragonet species, ''Calliurichthys japonicus'' and ''Repomucenus huguenini'', in Tosa Bay, Southern Japan|journal=Fisheries Science|year=1997|volume=63|issue=1|pages=15–21|doi=10.2331/fishsci.63.15}}</ref> This [[sexual dimorphism]] may have evolved in males in response to female [[mate choice]], male-male competition, or both.<ref name=Tosa/>

==Competition/aggression==

Male dragonets form [[dominance hierarchies]] and act extremely aggressively towards each other. They are often observed chasing and biting, which occurs primarily when two males are close to a female during courtship and pairing.<ref name=Laboratory/> Fights can be very intense; when one male recognizes another male near its breeding site, it will rush toward it and bite at its rival's mouth. The two may bite at each other and twist their bodies around one another for longer than a minute.<ref name=Behavior>{{cite journal|last=Harrington|first=Michael E.|title=Behavior patterns and sexual dimorphism in the spotted dragonet, ''Diplogrammus pauciradiatus'' (Pisces: Callionymidae)|journal=Bulletin of Marine Science|year=1997|volume=60|issue=3|pages=872–893}}</ref> As a result of this behavior, male dragonets suffer higher mortality rates than females do after attaining maturation.<ref name="Sex ratio">{{cite journal|last=Ikejima|first=Kou|author2=Makoto Shimizu|title=Sex ratio in the dragonet, ''Repomucenus valenciennei''|journal=Ichthyological Research |year=1999|volume=46|issue=4|pages=426–428|doi=10.1007/bf02673986|s2cid=38779696 }}</ref> The highest mortality rates in adult males occur during breeding. Males have evolved larger bodies, as well as longer spines and rays, in order to achieve dominance in reproduction. They have also developed bright colors so as to more effectively compete for female attention. These [[secondary sex characteristics]] further reduce the survival potential of male dragonets, as they increase the risk of predation, require greater energy costs, and escalate the risk of suffering injuries.<ref name=Maturation/>

==Feeding==

Feeding by the dragonet occurs throughout the day, including the intervals between courtships and spawning. The fish feeds entirely on [[benthic]] sources, primarily [[copepods]], [[amphipods]], and other small [[invertebrates]] living on blades of sea grass.<ref name=Dragonets>{{cite web|url=http://www.aquaticcommunity.com/Dragonets/|title=Dragonets|publisher=Aquatic Community|access-date=2013-11-15}}</ref> Species of dragonets from different locations show variations in specific food preference, attributable to the different availabilities and abundances of food organisms in those places. All of them feed by extending their highly protractible jaws toward their food and drawing it into the mouths, frequently followed by the expulsion of sand. No evidence suggests that dragonets are territorial. Individuals do not defend specific areas of substrate, as well as any resources that might be present on them, from intrusion by conspecifics or other fish species.<ref name=Behavior/>

Among ''Calliurichthys japonicus'' and ''Repomucenus huguenini'', the two most abundant dragonet species, amphipods are the most plentiful prey during the spring and winter months. The fish also supplement their diets with [[polychaetes]], [[bivalves]], and [[gastropods]] in these periods. During the summer, the dragonets feed primarily on [[ophiuroids]] and amphipods. In this season, ophiuroids are the most dominant in number. Finally, in the fall, the two species predominantly consume polychaetes, amphipods, and [[gastropods]], with polychaetes contributing the highest amount.<ref name=Diet>{{cite journal|last=Gonzales|first=Benjamin J.|author2=Nobuhiko Taniguchi |author3=Osamu Okamura |author4=Yoshihiko Machida |title=Diet and feeding behavior of two dragonets ''Calliurichthys japonicus'' and ''Repomucenus huguenini'' in Tosa Bay, Southern Japan|journal=Fisheries Science|year=1996|volume=62|issue=6|pages=902–908|doi=10.2331/fishsci.62.902|doi-access=free}}</ref>

==Locomotion==

Four types of swimming are observed in the dragonet. The first is burst swimming, the most common of the four, and utilized during [[foraging]]. The dragonet uses its pelvic fins to propel its body off of a [[substrate (biology)|substrate]], and then its pectoral fins to guide itself forward. The second is continuous swimming, often utilized by males when approaching a potential mate or retreating during an aggressive encounter with another male. The dragonet uses its pectoral fins to propel its body forward, and its pelvic fins to lift and guide itself. The third type of swimming is rapid swimming, which is observed when the dragonet is attacking or fleeing. The fish primarily uses its caudal fins to achieve a quick speed. Finally, the fourth type is vertical swimming, utilized by the dragonet during spawning when it ascends. The pectoral fins are used to propel the fish's body up the water column.<ref name=Behavior/>

==Defense==

In defense against its predators, the dragonet rapidly buries itself under the sand at the bottom of the ocean so that only its eyes remain visible. Many species of the fish also are capable of producing and secreting foul-tasting and -smelling substances that may ward off any potential predators.<ref name=Aqualog>{{cite journal|last=Frische|first=Joachim|title=The Fingered Dragonet Imposing presence – inconspicuous coloration|journal=Aqualog News|volume=90|pages=23–24}}</ref>

==Timeline==
<timeline>
ImageSize  = width:1000px height:auto barincrement:15px
PlotArea   = left:10px bottom:50px top:10px right:10px

Period      = from:-65.5 till:10
TimeAxis    = orientation:horizontal
ScaleMajor  = unit:year increment:5 start:-65.5
ScaleMinor  = unit:year increment:1 start:-65.5
TimeAxis    = orientation:hor
AlignBars   = justify

Colors =
 #legends
  id:CAR	  value:claret
  id:ANK 	 value:rgb(0.4,0.3,0.196)
  id:HER	  value:teal
  id:HAD	  value:green
  id:OMN	  value:blue
  id:black        value:black
  id:white        value:white
  id:cenozoic     value:rgb(0.54,0.54,0.258)
  id:paleogene     value:rgb(0.99,0.6,0.32) 
  id:paleocene     value:rgb(0.99,0.65,0.37) 
  id:eocene     value:rgb(0.99,0.71,0.42) 
  id:oligocene     value:rgb(0.99,0.75,0.48) 
  id:neogene     value:rgb(0.999999,0.9,0.1) 
  id:miocene     value:rgb(0.999999,0.999999,0) 
  id:pliocene     value:rgb(0.97,0.98,0.68)  
  id:quaternary   value:rgb(0.98,0.98,0.5)
  id:pleistocene   value:rgb(0.999999,0.95,0.68)
  id:holocene   value:rgb(0.999,0.95,0.88)
 
BarData=
 bar:eratop
 bar:space
 bar:periodtop
 bar:space
 bar:NAM1

 bar:space
 bar:period
 bar:space
 bar:era

PlotData=
 align:center textcolor:black fontsize:M mark:(line,black) width:25 
 shift:(7,-4)
  
 bar:periodtop
 from: -65.5   till:  -55.8    color:paleocene  text:[[Paleocene]]
 from: -55.8   till:  -33.9    color:eocene  text:[[Eocene]] 
 from: -33.9   till:  -23.03    color:oligocene  text:[[Oligocene]]            
 from: -23.03    till: -5.332    color:miocene    text:[[Miocene]]
 from: -5.332    till: -2.588    color:pliocene    text:[[Plio.]]
 from: -2.588    till: -0.0117   color:pleistocene    text:[[Pleist.]]
 from: -0.0117    till: 0    color:holocene    text:[[Holocene|H.]]

 bar:eratop
 from: -65.5   till:  -23.03    color:paleogene  text:[[Paleogene]]         
 from: -23.03    till: -2.588    color:neogene    text:[[Neogene]]
 from: -2.588    till: 0   color:quaternary    text:[[Quaternary|Q.]]

PlotData=
 align:left fontsize:M mark:(line,white) width:5 anchor:till align:left

 color:eocene bar:NAM1  from:	-55.8	till:	0	text:	[[Callionymus]]

PlotData=
 align:center textcolor:black fontsize:M mark:(line,black) width:25

 bar:period
 from: -65.5   till:  -55.8    color:paleocene  text:[[Paleocene]]
 from: -55.8   till:  -33.9    color:eocene  text:[[Eocene]] 
 from: -33.9   till:  -23.03    color:oligocene  text:[[Oligocene]]            
 from: -23.03    till: -5.332    color:miocene    text:[[Miocene]]
 from: -5.332    till: -2.588    color:pliocene    text:[[Plio.]]
 from: -2.588    till: -0.0117   color:pleistocene    text:[[Pleist.]]
 from: -0.0117    till: 0    color:holocene    text:[[Holocene|H.]]

 bar:era
 from: -65.5   till:  -23.03    color:paleogene  text:[[Paleogene]]         
 from: -23.03    till: -2.588    color:neogene    text:[[Neogene]]
 from: -2.588    till: 0   color:quaternary    text:[[Quaternary|Q.]]

</timeline>

==See also==
*[[List of fish common names]]
*[[List of fish families]]

==References==
{{Reflist|30em}}

==External links==
* Smith, J.B.L. 1963. [http://hdl.handle.net/10962/d1019785 Fishes of the families Draconettidae and Callionymidae from the Red Sea and the Western Indian Ocean. Ichthyological Bulletin; No. 28]. Department of Ichthyology, Rhodes University, Grahamstown, South Africa
{{Wikispecies|Callionymidae}}
{{commons category-inline|Callionymidae}}

{{Taxonbar|from=Q688312}}

[[Category:Callionymidae| ]]
[[Category:Taxa named by Charles Lucien Bonaparte]]