Halfbeak 333163 220582891 2008-06-20T15:41:23Z DOI bot 6652755 Citation maintenance. You can [[WP:DOI|use this bot]] yourself! Please [[User:DOI_bot/bugs|report any bugs]]. {{Taxobox | fossil_range = [[Eocene]] - Recent | name = Hemiramphidae | image = Hemiramphus brasiliensis (line art).jpg | image_caption = A marine halfbeak, the ballyhoo, ''[[Hemiramphus brasiliensis]]'' | image_width = 250px | regnum = [[Animal]]ia | phylum = [[Chordate|Chordata]] | classis = [[Actinopterygii]] | ordo = [[Beloniformes]] | subordo = [[Belonoidei]] | superfamilia = [[Exocoetoidea]] | familia = '''Hemiramphidae''' | familia_authority = [[Theodore Nicholas Gill|Gill]], 1859 | subdivision_ranks = [[Scientific classification|Subfamilies]] and [[Genus|Genera]] | subdivision = '''Hemiramphinae'''&nbsp;<small>Gill, 1859</small><br /> &nbsp;&nbsp;''[[Arrhamphus]]''<br /> &nbsp;&nbsp;''[[Chriodorus]]''<br /> &nbsp;&nbsp;''[[Euleptorhamphus]]''<br /> &nbsp;&nbsp;''[[Hemiramphus]]''<br /> &nbsp;&nbsp;''[[Hyporhamphus]]''<br /> &nbsp;&nbsp;''[[Melapedalion]]''<br /> &nbsp;&nbsp;''[[Rhynchorhamphus]]''<br /> '''Zenarchopterinae'''&nbsp;<small>[[Henry Weed Fowler|Fowler]],&nbsp;1934</small><br /> &nbsp;&nbsp;''[[Dermogenys]]''<br /> &nbsp;&nbsp;''[[Hemirhamphodon]]''<br /> &nbsp;&nbsp;''[[Nomorhamphus]]''<br /> &nbsp;&nbsp;''[[Tondanichthys]]''<br /> &nbsp;&nbsp;''[[Zenarchopterus]]'' }} The '''halfbeaks''' ([[family (biology)|family]] '''Hemiramphidae''') are a geographically widespread and numerically abundant [[Family (biology)|family]] of [[epipelagic]] [[fish]] inhabiting warm waters around the world. The family Hemiramphidae is divided into two subfamilies, the primarily [[Marine (ocean)|marine]] Hemiramphinae and the [[fresh water|freshwater]] or [[estuary|estuarine]] Zenarchopterinae. The halfbeaks are named for their distinctive jaws, in which the lower jaws are significantly longer than the upper jaws. The halfbeaks are remarkable for showing an exceptionally wide range of [[Biological reproduction|reproductive]] modes. These include [[oviparity|egg-laying]], [[ovoviviparity]], and true [[vivipary]] where the mother is connected to the developing embryos via a [[placenta]]-like structure. In some of the [[Live-bearing aquarium fish|livebearing]] species, developing [[embryo]]s are also known to exhibit [[oophagy]] or [[intrauterine cannibalism]], where developing embryos feed on eggs or other embryos within the uterus. Though not [[fishing|commercially important]] themselves, these fish support [[artisan fishing|artisanal fisheries]] and local markets worldwide. They are also fed upon by other commercially important [[predator]]y fishes, such as [[billfish]]es, [[mackerel]]s, and [[shark]]s. Some halfbeaks are maintained as [[aquarium]] fish in the [[fishkeeping]] hobby. ==Taxonomy== The first halfbeak to be [[scientific classification|scientifically described]] was ''[[Esox]] brasiliensis'', by [[Carolus Linnaeus]] in 1758. Two more species were described as ''Esox'', ''[[Hemiramphus far|Esox far]]'' and ''[[Hemiramphus marginatus|Esox marginatus]]'', by [[Peter Forsskål]] in 1775. It was not until 1816 that [[Georges Cuvier]] created the genus ''Hemiramphus''; from then on, these three species were classified as ''Hemiramphus'' species. Hemiramphidae was erected by [[Theodore Nicholas Gill|Gill]] in 1859, deriving its name from ''Hemiramphus'', the family's [[biological type|type genus]].<ref name="Collette"/> The name comes from the [[Ancient Greek|Greek]] ''hemi'', meaning half, and ''rhamphos'', meaning a beak or bill.<ref name="fishbase">{{FishBase family|family=Hemiramphidae|year=2007|month=Aug}}</ref> [[Image:Oxyporhamphus micropteru 545.jpg|thumb|250px|right|''Oxyporhamphus micropterus'' has been considered either a halfbeak or a flyingfish.]] The family Hemiramphidae is currently divided into two subfamilies, the Hemiramphinae and the Zenarchopterinae, each containing about half the known species. In a 2004 review of the family, two subfamilies, 13 genera, and 117 species and subspecies were recognised.<ref name="Collette"/> More recently, Hemiramphidae has been listed to include 12 genera and about 109 species, with the genus ''[[Oxyporhamphus]]'' moved to [[Exocoetidae]].<ref name="Nelson">{{cite book|title=[[Fishes of the World]]|last=Nelson|first=Joseph S.|publisher=[[John Wiley & Sons]], Inc|year=2006|pages=278&ndash;280|isbn=0-471-25031-7}}</ref> The Hemiramphinae are primarily [[Marine biology|marine]] and found in the [[Atlantic]], [[Pacific]], and [[Indian Ocean]]s, though some inhabit [[estuary|estuaries]] and [[river]]s. The Zenarchopterinae are confined to the [[Indo-West Pacific]] [[Zoogeography|zoogeographic]] region, an area running from [[East Africa]] to the [[Caroline Islands]]. The Zenarchopterinae are remarkable for exhibiting strong [[sexual dimorphism]], practicing [[internal fertilisation]], and in some cases being [[ovoviviparous]] or [[viviparous]]. Three genera in this subfamily are exclusively [[freshwater fish]] and several, such as the [[wrestling halfbeak]], have become commonly traded [[fishkeeping|aquarium fish]].<ref name="Collette"/> It is believed by some authors that the recognition of Zenarchopterinae as a separate family (Zenarchopteridae) probably should be accepted.<ref name="Nelson"/><ref name="Lovejoy"/> ==Evolution== The [[fossil record]] of the halfbeaks extends into the [[Palaeogene|Lower Tertiary]].<ref name="fishbase"/> The earliest known halfbeak is ''Brachyrhamphus bolcensis'' from the [[Eocene]] at Monte [[Bolca]], Italy.<ref name="Frickhinger">{{cite book|title=Fossil Atlas: Fishes|last= Frickhinger|first=K. A.|publisher= Mergus|year=1995|isbn=1-56465-115-0}}</ref> Apart from differences in the length of the upper and lower jaws, [[Holocene|recent]] and fossil halfbeaks are distinguished by the fusion of the third pair of upper pharyngeal bones into a plate.<ref name="Lovejoy"/> ==Phylogeny== {{userboxtop| toptext=&nbsp;}} {{clade| |1={{clade |1={{clade |label1=&nbsp;&nbsp; |1=[[Belonidae]]+[[Scomberoscocidae]]&nbsp; |label2=&nbsp;&nbsp; |2={{fontcolor|||'''[[Zenarchopterinae]]'''}} }} |2={{clade |label1=&nbsp;&nbsp; |1={{fontcolor|||'''[[Hemiramphinae]]''' }} |label2=&nbsp;&nbsp; |2=[[Exocoetidae]] }} }} |label2=&nbsp;&nbsp; |2=[[Adrianichthyidae]] }} <center><small>[[Phylogeny]] of the halfbeaks. The halfbeak [[Family (biology)|family]] Hemiramphidae (Zenarchopterinae + Hemirhamphinae) is [[paraphyletic]].<ref>Nathan R. Lovejoy, Mahmood Iranpour, and Bruce B. Collette. 2004. Phylogeny and Jaw Ontogeny of Beloniform Fishes, Integrative and Comparative Biology 44(5):366-377</ref></small></center> {{userboxbottom}} The [[phylogeny]] of the halfbeaks is controversial and currently in a state of flux. On the one hand, there is little question that they are most closely related to three other families of streamlined, surface water fishes: the [[flyingfish]]es, [[needlefish]]es, and [[saury|sauries]].<ref name="Helfman">{{cite book|title=The Diversity of Fishes|last=Helfman|first=Gene S.|coauthors=Collette, Bruce B.; Facey, Douglas E.|publisher=[[Blackwell Publishing]]|year=1997|pages=274&ndash;276|isbn=0-86542-256-7}}</ref> Traditionally, these four families have been taken to together comprise the order [[Beloniformes]].<ref name="Helfman"/> The halfbeaks and flyingfishes are considered to form one group, the superfamily [[Exocoetoidea]], and the needlefishes and sauries another, the superfamily [[Scomberesocoidea]].<ref name="Nelson"/> On the other hand, recent studies have demonstrated that rather than forming a single [[monophyletic]] group (a [[clade]]), the halfbeak family actually includes a number of lineages ancestral to the flyingfishes and the needlefishes. In other words, as traditionally defined, the halfbeak family is [[paraphyletic]].<ref name="Lovejoy"/> Within the subfamily Hemiramphinae, the "flying halfbeak" genus ''Oxyporhamphus'' has proved to be particularly problematical; while [[Morphology (biology)|morphologically]] closer to the flyingfishes, molecular evidence places it with ''Hemiramphus'' and ''Euleptorhamphus''. Together, these three genera form the [[cladistics|sister group]] to the flyingfish family.<ref name="Lovejoy"/> The other two hemiramphine genera ''Hyporhamphus'' and ''Arrhamphus'' form another clade of less clear placement.<ref name="Lovejoy"/> Rather than being closely related to the flyingfishes, the subfamily Zenarchopterinae appears to be the sister group of the [[needlefish]]es and [[saury|sauries]]. These is based on the pharyngeal jaw apparatus, sperm ultrastructure, and molecular evidence. However, this hypothesis has awkward implications for how the morphological evolution of the group is understood, because the fused pharyngeal plate has been considered reliably diagnostic of the halfbeak family.<ref name="Lovejoy"/> Furthermore, the existing theory that because juvenile needlefish pass through a [[developmental biology|developmental]] stage where the lower jaw is longer than the upper jaw (the so-called "halfbeak stage") the theory that halfbeaks are [[Pedomorphosis|paedomorphic]] needlefish is untenable.<ref name="Lovejoy"/> In fact the unequal lengths of the upper and lower jaws of halfbeaks appears to be the [[Basal (phylogenetics)|basal]] condition, with needlefish being relatively [[derived]] in comparison.<ref name="Lovejoy">{{cite journal|last=Lovejoy|first=N|coauthors=Iranpour, M; Collette, B|title=Phylogeny and Jaw Ontogeny of Beloniform Fishes|journal=Integrative and Comparative Biology|volume=44|pages=366–377|year=2004|url=http://icb.oxfordjournals.org/cgi/content/full/44/5/366|doi=10.1093/icb/44.5.366}}</ref><ref>{{cite journal|last=Boughton|first=D|coauthors=Collette, B; McCune, A.|title=Heterochrony in Jaw Morphology of Needlefishes (Teleostei: Belonidae)|journal=Systematic Zoology|volume=40|pages=329–352|year=1991|doi=10.2307/2992326}}</ref> ==Morphology== [[Image:Labelled H pogonognathus.jpg|thumb|250px|right|''Hemirhamphodon pogongnathus'' with key morphological features labelled; note the great length of the lower jaw compared with the upper jaw.]] The halfbeaks are elongate, streamlined fish adapted to living in open water. Halfbeaks range in size from 4&nbsp;[[centimetre]]s (1.6&nbsp;[[inch|in]]) [[fish measurement|standard length (SL)]] in ''[[Hemirhamphodon tengah]]'' to over 40&nbsp;cm (16&nbsp;in) SL in the case of ''[[Euleptorhamphus|Euleptorhampus viridis]]''. The [[Scale (zoology)|scales]] are relatively large, [[Cycloid scale#Scales|cycloid]] (smooth), and easily detached. There are no spines in the fins.<ref name="Collette"/> A peculiarity shared by all halfbeaks that distinguishes them from the other fishes in the Beloniformes is that the third pair of upper pharyngeal bones are anklylosed (fused) into a plate. Halfbeaks are one of a number of fish families that lack a [[stomach]], all of which possess a pharyngeal jaw apparatus (pharyngeal mill).<ref name="Nelson"/> Most species have an extended lower jaw, at least as juveniles, though this feature may be lost as the fish mature, as with ''Chriodorus'', for example.<ref name="Lovejoy"/> As is typical for surface dwelling, open water fish, most species are silvery, and darker above and lighter below, an example of [[countershading]]. The tip of the lower jaw is bright red or orange in most species.<ref name="Collette"/> Small patches of colour, particularly among males, are only found on the fins and the tip of the beak.<ref name="Riehl1">{{cite book|last=Riehl|first=R|coauthors=Baensch, H|title=Aquarium Atlas (vol. 1)|publisher=Voyageur Press|year=1996|isbn=3-88244-050-3}}</ref> Halfbeaks demonstrate a number of adaptations to feeding at the surface of the water. The eyes and nostrils are at the top of the head and it is the upper jaw that is mobile, not the lower jaw. Combined with their streamlined shape and the concentration of fins towards the back (similar to that of a [[Esox|pike]]), these adaptations allow halfbeaks to locate, catch, and swallow food items very effectively.<ref name="Hoedeman"/> ===Sexual dimorphism=== [[Sexual dimorphism]] is apparent in some species of halfbeak. Males of the ovovivaparous and vivaparous species all have a modified anal fin, the ''andropodium'', similar to the [[gonopodium]] of [[Poecilidae|poecilid]] livebearers, used to deliver sperm to the females.<ref name="Hoedeman"/> Although most of the egg laying species mate by shedding the [[milt]] externally, as is typical for [[bony fish]], at least some egg-laying species practise internal fertilisation: male ''[[Zenarchopterus]]'' use a modified anal fin to direct sperm into the genital opening of the female prior to spawning.<ref>{{cite journal|last=Kottelat|first=M|coauthors=Lim, K|title=Mating Behaviour of ''Zenarchopterus gilli'' and ''Zenarchopterus buffonis'' and Function of the Modified Dorsal and Anal Fin Rays in Some Species of ''Zenarchopterus'' (Teleostei: Hemiramphidae)|journal=[[Copeia]]|issue=4|pages=1097&ndash;1101|year=1999|doi=10.2307/1447985|volume=1999}}</ref> Besides modifications to the anal fin, other differences include size, colouration, and the length or shape of the beak. Female ''Normorhamphus'' are much larger than males but aren't as brightly coloured and have shorter beaks.<ref name="Riehl1"/> By contrast, male ''Hemirhamphodon'' are larger than the females, and some species, such as ''Hemirhamphodon pogonognathus'', also have a long beard-like tassle on the end of the beak.<ref name="Riehl2">{{cite book|last=Riehl|first=R|coauthors=Baensch, H|title=Aquarium Atlas (vol. 2)|publisher=Microcosm Ltd|year=1997|isbn=1-890087-06-8}}</ref> ==Distribution== [[Image:Halfbeak 600.jpg|thumb|250px|right|A marine halfbeak, ''Hemiramphus balao''.]] Halfbeaks are found in warm seas, predominantly at the surface, occurring in the [[Atlantic]], [[Indian Ocean|Indian]], and [[Pacific]] oceans.<ref name="Nelson"/> A small number are found in estuaries and some species, including all the species in the genera ''[[Dermogenys]]'', ''[[Hemirhamphodon]]'', ''[[Nomorhamphus]]'', and ''[[Tondanichthys]]'' are confined to freshwaters.<ref>{{cite journal|last=Collette|first=Bruce|title=''Tondanichthys kottelati'', a new genus and species of freshwater halfbeak (Teleostei: Hemiramphidae) from Sulawesi|journal=Ichthyological Exploration of Freshwaters|volume=6|pages=171–174|year=1995}}</ref> Most species of marine halfbeaks are known from continental coastlines, but some extend into the western and central [[Pacific]], and one species is [[endemism|endemic]] to [[New Zealand]].<ref name="Nelson"/> ''Hemiramphus'' is a worldwide marine genus.<ref name=fishbase/> The freshwater halfbeaks all occur in freshwater or estuaries in the [[Indo-West Pacific]] region.<ref name="Nelson"/> There is a particularly high concentration of species on the island of [[Celebes]].<ref name="all_livebearers"/> ==Ecology and behavior== ===Diet=== Marine halfbeaks are [[omnivore]]s feeding on [[algae]]; marine plants such as [[seagrass]]es; [[plankton]]; invertebrates such as [[Sea butterfly|pteropods]] and [[crustaceans]]; and smaller fishes.<ref>{{cite journal|last=Randall|first=J|url=http://www.aoml.noaa.gov/general/lib/CREWS/Cleo/PuertoRico/prpdfs/randall-habits.pdf|title=Food habits of reef fishes of the West Indies|journal=Studies in Tropical Oceanography|volume=5|pages=665–847|year=1967|format=[[PDF]] Converted to digital format by [[NOAA]], 2004}}</ref> For some subtropical species at least, juveniles are more predatory than adults. Some tropical species have been observed to feed on animals during the day and plants at night, while other species alternate between carnivory in the summer and herbivory in the winter.<ref name="Tibbetts">{{cite journal|last=Tibbetts|first=I|coauthors=Carseldine, L|title=Trophic shifts in three subtropical Australian halfbeaks (Teleostei: Hemiramphidae)|journal=Marine & Freshwater Research|volume=56|pages=925–932|year=2005|doi=10.1071/MF04305}}</ref> They are in turn eaten by many ecologically and [[Fishing|commercially important]] predatory fish, such as [[billfish]], [[mackerel]], and [[shark]]s, and so are a key link between [[trophic level]]s.<ref name="Mahmoudi">{{cite web|last=Mahmoudi|first=B|coauthors=McBride, R|title=A review of Florida’s halfbeak bait fishery and halfbeak biology, and a preliminary stock assessment|url=http://research.myfwc.com/images/articles/17405/bally_2002rff_3251.pdf|publisher=Florida Fish and Wildlife Conservation Commission|year=2002|format=[[PDF]]}}</ref> The freshwater species are more predatory than the marine species, and typically orient themselves into the water current and take aquatic insect larvae, such as [[midge]] larvae, and small insects, such as [[fly|flies]] that have fallen on the surface of the water, particularly [[mosquito]]es and [[spider]]s.<ref name="Hoedeman">{{cite book|last=Hoedeman|first=J.|title=Naturalist's Guide to Freshwater Aquarium Fish|publisher=[[Elsevier]]|pages=724–729|year=1974|isbn=0-8069-3722-X}}</ref><ref>{{cite web|url=http://www.ecologyasia.com/verts/fresh-fishes/forest-halfbeak.htm|title=Forest Halfbeak|publisher=EcologyAsia|accessdate=2006-09-03}}</ref><ref>{{cite web|url=http://www.ecologyasia.com/verts/fresh-fishes/pygmy-halfbeak.htm|title=Pygmy Halfbeak|publisher=EcologyAsia|accessdate=2006-09-03}}</ref> ===Behaviour=== Marine halfbeaks are typically [[pelagic]] [[swarm|schooling]] fish that swim close to the surface of the sea.<ref name="McGarvey"/><ref name="Stewart"/> The southern sea garfish ''Hyporhamphus melanochir'' for example is found in sheltered bays, coastal seas, estuaries around southern Australia in waters down to a depth of 20&nbsp;[[metre|m]] (66&nbsp;[[foot (unit of length)|ft]]). These fish form schools near the surface at night but swim closer to the sea floor during the day, particularly among beds of [[seagrass]]es.<ref name="Lyle"/> Genetic analysis of the different [[population biology|sub-populations]] of the eastern sea garfish ''Hyporhamphus melanochir'' in South Australian coastal waters reveals that there is a small but consistent migration of individuals between each sub-population, sufficient to keep them genetically homogenous.<ref name="McGarvey"/> Freshwater halfbeaks vary in social behaviour from open water schooling fish similar to the marine halfbeaks, as with species of ''Zenarchopterus'',<ref name ="SchaferBWF"/> through to much more aggressive and combative fishes, as is best known with the "wrestling" halfbeaks of the genus ''Dermogenys''.<ref name ="Sterba"/> These non-schooling freshwater halfbeaks prefer to lurk among aquatic plants such as [[Reed (plant)|reeds]], dead trees, and artificial structures of various types; from there they will wait for small prey animals to drift by or alight on the surface, and then the halfbeak will dart out of their hiding place to capture its prey.<ref name ="Hoedeman"/> Notably, these freshwater halfbeaks feed extensively on female mosquitoes that are laying their eggs in the water, making them much better at mosquito control that species like [[guppies]] and [[mosquitofish]] that only take mosquito larvae.<ref name="Hoedeman"/> Some marine halfbeaks, including ''Euleptorhamphus velox'' and ''Euleptorhamphus viridis'', are know for their ability to jump out of the water and glide over the surface for considerable distances, and have consequently sometimes been called '''flying halfbeaks'''.<ref name="fishbase"/><ref>{{FishBase species|genus=Euleptorhamphus|species=velox|year=2007|month=Aug}}</ref><ref>{{FishBase species|genus=Euleptorhamphus|species=viridis|year=2007|month=Aug}}</ref> ===Reproduction=== [[Image:halfbeak fry.jpeg|thumb|250px|right|Young freshwater halfbeak, ''Nomorhamphus'' sp., aged 7&nbsp;days, approximately 18&nbsp;mm (0.71&nbsp;in) in length. Captive bred specimen.]] Halfbeaks exhibit a remarkably wide variety of reproductive modes ranging from straightforward egg-laying ([[oviparous|oviparity]]) through to various form of [[Live-bearing aquarium fish|livebearing]] ([[ovoviviparity]] and [[viviparous|viviparity]]). There is a taxonomic split in this however: all Hemiramphinae are egg-layers, while many of the Zenarchopterinae are either ovoviviparous or viviparous. ====Oviparity in the Hemiramphinae==== Hemiramphinae species are all external fertilizers.<ref name="Nelson"/> They are usually egg-layers and often produce relatively small numbers of fairly large eggs for fish of their size, typically in shallow coastal waters, such as the [[seagrass]] meadows of [[Florida Bay]].<ref name="McBride">{{cite journal|url=http://www.biolbull.org/cgi/content/abstract/204/1/57|title=Reproductive Biology of ''Hemiramphus brasiliensis'' and ''H. balao'' (Hemiramphidae): Maturation, Spawning Frequency, and Fecundity (abstract)|first=Richard S.|last=McBride|coauthors=Thurman, Paul E.|journal=Biol. Bull.|volume=204|pages=57–67|date=February 2003|doi=10.2307/1543496|pmid=12588745}}</ref> The eggs of ''Hemiramphus brasiliensis'' and ''H. balao'' are typically 1.5&ndash;2.5&nbsp;[[millimetre]]s (0.059&ndash;0.098&nbsp;in) in diameter and have attaching filaments. They hatch when they are about 4.8&ndash;11&nbsp;mm (0.19&ndash;0.43&nbsp;in) in diameter.<ref name="Collette"/> ''Hyporhamphus melanochir'' eggs are slightly larger, around 2.9&nbsp;[[millimetre]]s in diameter, and are unusually large when they hatch, being up to 8.5&nbsp;[[millimetre]]s in size.<ref name="Lyle"/> Relatively little is known about the ecology of juvenile marine halfbeaks after hatching, though estuarine habitats seem to be favoured by at least some species.<ref name="Lyle"/><ref name="McBride"/> The southern sea garfish ''Hyporhamphus melanochir'' grows rapidly at first, attaining a length of up to 30&nbsp;[[centimetre]]s in the first three years, after which point growth slows down.<ref name="Lyle"/> This species lives for a maximum age of about 9 years, at which point the fish will be up to 40&nbsp;[[centimetre]]s and weigh about 0.35&nbsp;[[kilogramme]]s.<ref name="Lyle"/> ====Viviparity in the Zenarchopterinae==== [[Image:Dermogenys sumatrana 02.jpg|thumb|250px| right |Female ''Dermogenys sumatrana'' a day or so before giving birth.]] The freshwater halfbeaks of the genera ''Dermogenys'', ''Hemirhamphodon'', and ''Nomorhamphus'' are all livebearers, that is, they do not lay eggs but instead produce well-developed free-swimming young. However, there is a great deal of variation in the details. Meisner and Burns identified no fewer than five distinct modes of [[viviparous|viviparity]] and [[Ovoviviparity|ovovivparity]] in the freshwater halfbeaks:<ref name="Meisner">{{cite journal|last=Meisner|first=A|coauthors=Burns, J|title=Viviparity in the Halfbeak Genera ''Dermogenys'' and ''Nomorhamphus'' (Teleostei: Hemiramphidae)|journal=Journal of Morphology|volume=234|pages=295–317|year=1997|doi=10.1002/(SICI)1097-4687(199712)234:3<295::AID-JMOR7>3.0.CO;2-8}}</ref> * '''Type 1:''' Fertilised eggs retained within the [[ovarian follicle]]. [[Superfetation]], that is storage of sperm, does not occur. The eggs are provided with a large [[yolk sac]] and have little or no connection to the maternal blood supply. Example: Southeast Asian populations of ''Dermogenys pusilla''. * '''Type 2:''' Fertilised eggs retained within the ovarian follicle. Superfetation does occur, with up to three broods resulting from a single mating. The eggs are provided with a small yolk sac but the embryos instead have a connection to the maternal supply through the [[body cavity|coelomic cavity]] and [[pericardium|pericardial sac]]. Examples: ''Dermogenys pusilla'' from Sabah and ''Dermogenys orientalis''. * '''Type 3:''' Fertilised eggs retained within the ovarian follicle only for the early stages of development, with the embryos later developing along the full length of the [[ovary]]. Superfetation does occur, and up to two broods can develop simultaneously in the ovary. The eggs are provided with a small yolk sac but the embryos have a connection to the maternal supply through an expanded belly sac. Example: ''Dermogenys viviparus''. * '''Type 4:''' Fertilised eggs retained within the ovarian follicle only for the early stages of development, with the embryos later developing along the full length of the ovary. Superfetation does not occur. The eggs are provided with a large yolk sac and the embryos have no connection to the maternal blood supply. Examples: ''Nomorhamphus megarrhamphus'', ''Nomorhamphus weberi'', and ''Nomorhamphus towoetii''. * '''Type 5:''' Fertilised eggs retained within the ovarian follicle only for the early stages of development, with the embryos later developing along the full length of the ovary. Superfetation does occur, and embryos of different ages can be found in the ovaries. The eggs are provided with a small yolk sac and the embryos only have a connection to the maternal blood supply for only part of their development. Late-stage embryos appear to eat eggs and small embryos in ovary.<ref name="Meisner"/> Note that embryos eating eggs and other embryos has been observed in a few other fishes, most notably sharks (see article on [[oophagy]]). Example: ''Nomorhamphus ebrardtii''. As with other livebearing fish, freshwater halfbeaks produce small broods of large offspring compared with egg-laying species of similar size, with broods of around ten to twenty, 10–15&nbsp;mm long offspring being typical.<ref name="keepnbreed">{{cite web|url=http://homepage.mac.com/nmonks/aquaria/halfbeakbreeding.html|title=Keeping & Breeding Halfbeaks|accessdate=2006-09-03}}</ref> ==Relationship to humans== ===Halfbeak fisheries=== Halfbeaks are not a major target for [[Fishing|commercial fisheries]], though small fisheries for them exist in some places, for example in [[South Australia]] where fisheries target the southern sea garfish (''Hyporhamphus melanochir'').<ref name="McGarvey">{{cite journal |first=R. |last= McGarvey |coauthors=Fowler, A. J., Feenstra, J. E., and Jackson, W. B. | title=Garfish (''Hyporhamphus melanochir'') Fishery, Fishery Assessment Report to PIRSA for the Marine Scalefish Fishery Management Committee|journal=SARDI Research Report Series|volume=163 |year=2006 |pages=1–55}}</ref> and the eastern sea garfish (''Hyporhamphus australis'').<ref name="Stewart">{{cite journal |first=John|last= Stewart|title=An observer-based assessment of the estuarine fishery for eastern sea garfish (''Hyporhamphus australis'') in Australia|journal=NSW Department of Primary Industries – Fisheries Final Report Series|volume=87 |year=2007 |pages=1–14}}</ref> Halfbeaks are caught by a variety of methods including [[seine (fishing)|seine]]s and pelagic [[trawl]]s, dip-netting under lights at night, and with haul nets.<ref name="Collette"/> They are utilized fresh, dried, smoked, or salted,<ref name="Collette"/><ref name="McGarvey"/><ref name="Stewart"/> and they are considered good eating.<ref name="Sterba"/> However, even where halfbeaks are targeted by fisheries, they tend to be of secondary importance compared with other edible fish species.<ref name="Lyle">{{cite journal |first=J. M.|last= Lyle|coauthors=Jordan, A. R.|title=Tasmanian Scaleless Fisheries Assessment|journal=Tasmanian Aquaculture and Fisheries Institute Fishery Assessment Reports|volume=1 |year=1988 |pages=1–87}}</ref> In some localities significant [[bait fish]]eries exist to supply [[Game fish|sport fishermen]].<ref name="Tibbetts"/><ref name="Mahmoudi"/><ref name="Collette">{{cite web|last=Collette|first=Bruce B.|title=Family Hemiramphidae Gill 1859 &ndash; Halfbeaks|url=http://www.calacademy.org/research/ichthyology/annotated/checklists/Hemiramphidae.pdf|publisher=California Academy of Sciences Annotated Checklist of Fishes|issue=22|date=February 2004|format=[[PDF]]}}</ref> One study of a bait fishery in Florida that targets ''Hemiramphus brasiliensis'' and ''Hemiramphus balao'' suggests that despite increases in the size of the fishery the population is stable and the annual catch is valued at around $500,000.<ref name="Mahmoudi"/><ref>{{cite web|url=http://www.nmfs.noaa.gov/mb/sk/saltonstallken/halfbeak.htm|title=Status and Trends of Florida’s Halfbeak Fishery|accessdate=2007-02-10}}</ref> ===In the aquarium=== [[Image:N liemi bagged.JPG|thumb|250px| right |''Nomorhamphus liemi liemi'' halfbeaks ready for introduction to a new aquarium.]] Some of the smaller freshwater species are kept as [[aquarium]] fish in the ornamental [[fishkeeping]] [[hobby]].<ref name="MonksBWF">{{cite book|last=Monks|first=Neale (editor)|title=Brackish Water Fishes|journal=[[Tropical Fish Hobbyist]]|year=2006|isbn=0-7938-0564-3}}</ref> Species of the genera ''Dermogenys'' and ''Nomorhamphus'' are quite commonly kept as aquarium fish; species of ''Hemirhamphodon'' and ''Zenarchopterus'' are rather less commonly seen.<ref>{{cite book|last=Dawes|first=J|title=Livebearing Fishes: A Guide To Their Aquarium Care, Biology and Classification|publisher=Blandford|year=1995|isbn=0-7137-2592-3}}</ref><ref name="Riehl2"/><ref name="all_livebearers">{{cite book|last=Schäfer|first=F|coauthors=Kemkes, M.|title=All Livebearers and Halfbeaks|publisher=Aqualog|year=1998|isbn=3-931702-77-4}}</ref><ref name="SchaferBWF">{{cite book|last=Schäfer|first=Frank|title=Brackish Water Fishes|publisher=Aqualog|year=2005|isbn=3-936027-82-X}}</ref> They are small and generally peaceful towards other species, although males can be aggressive to one another.<ref name="keepnbreed"/> Male ''Dermogenys pusillius'' in particular fight vigorously and sometimes these battles end in injuries; this fish has therefore become known as the [[wrestling halfbeak]] and in some [[Asia]]n countries fights between males are used for betting purposes in much the same way as the [[Betta|Siamese fighting fish]].<ref name="Sterba">{{cite book|last=Sterba|first=G|title=Freshwater Fishes of the World|pages=609|publisher=Vista Books|year=1962}}</ref><ref>{{cite web|url=http://habitatnews.nus.edu.sg/guidebooks/freshfish/text/105.htm|title=Freshwater Fishes and the Singaporean|accessdate=2007-01-25}}</ref> To be kept successfully, halfbeaks require an aquarium with plenty of space at the surface. Depth is not critical, so a tank that is wide is better than one that is deep. They are sensitive to low [[oxygen saturation|oxygen levels]] but are otherwise relatively hardy, with one important exception: they are intolerant to sudden changes in [[salinity]], [[pH]], [[hard water|hardness]], or [[temperature]]. Consequently, they must be introduced to a new aquarium gently, and subsequent water changes are best small but frequent so the water chemistry does not change suddenly.<ref>{{cite web|url=http://www.mn-aquarium.org/articles/masart23.htm|title=Halfbeaks|first=Roger|last=Fischer|date=January/February 1994|publisher=Aqua News|accessdate=2006-09-03}}</ref> A few species, most notably ''Dermogenys pusillius'', have traditionally been kept in slightly [[brackish]] water, though some authors disputer this and suggest that reports that these fish come from brackish water come from the misidentification of juvenile estuarine and marine halfbeaks as adult freshwater halbeaks.<ref name="MonksBWF"><ref name="SchaferBWF"/> Most of the traded species of ''Nomorhamphus'' and ''Hemirhamphodon'' are known to prefer soft, neutral to slightly acid, freshwater conditions.<ref name="keepnbreed"/><ref>{{cite journal|last=Monks|first=Neale|title=Life at the Top|journal=[[Tropical Fish Hobbyist]]|date=November 2006}}</ref> Halfbeaks are nervous fish and shocks like sudden changes in illumination can cause them to swim around the tank frantically. They may hit themselves on the glass, injuring their beaks, or jump out of the tank completely. Injuries to the beak usually heal within a few weeks. They will eat insect larvae such as bloodworms readily, as well as crustacean eggs, shrimps, fruit flies, and even small pieces of chopped white fish. Halfbeaks sometimes eat flake foods as well. Some aquarists also offer them tiny pieces of algae wafer on the basis that most species are omnivorous in the wild, and so a certain amount of green food probably does them good.<ref>{{cite journal|last=Monks|first=Neale|title=Straight to the point: the Beloniformes|journal=Practical Fishkeeping|date=October 2005}}</ref> Halfbeaks will breed in captivity, but despite being [[Live-bearing aquarium fish|livebearers]] they are not particularly easy to breed.<ref name="keepnbreed"/> Miscarriages are common, particularly if the females are stressed or shocked (for example, by being moved to another aquarium). Once the fry have been born, things get much simpler, as the baby halfbeaks are quite big and will eat newly hatched [[brine shrimp]]s, small live foods such as [[daphnia]], and powdered [[fish flake|flake]].<ref>{{cite web|url=http://okcaa.org/articles/Blewett%20Dermogenys%20pusillus.pdf|title=Dermogenys pusillus - The Wrestling Halfbeak Livebearer|first=Earl|last=Blewett|format=[[PDF]]|accessdate=2006-09-03}}</ref> ==Conservation status== A small number of freshwater halfbeaks are listed in various [[IUCN Red List#Categories|categories]] on the [[IUCN]] [[IUCN Red List|Red List]] defining their risk of extinction. None of these species are traded as aquarium fish. Most are simply rare in the wild, and consequently at particular risk from [[habitat destruction]]. *''Dermogenys megarramphus'' – Lower Risk, Near Threatened<ref>{{IUCN2006|assessors=Kottelat, M.|id=6495|title=Dermogenys megarramphus|year=1996|downloaded=2007-02-10}}</ref> *''Dermogenys weberi'' – Vulnerable<ref>{{IUCN2006|assessors=Kottelat, M.|id=6496|title=Dermogenys weberi|year=1996|downloaded=2007-02-10}}</ref> *''Nomorhamphus celebensis'' – Data Deficient<ref>{{IUCN2006|assessors=Kottelat, M.|id=40693|title=Nomorhamphus celebensis|year=1996|downloaded=2007-02-10}}</ref> *''Nomorhamphus towoeti'' – Vulnerable<ref>{{IUCN2006|assessors=World Conservation Monitoring Centre|id=14834|title=Nomorhamphus towoeti|year=1996|downloaded=2007-02-10}}</ref> *''Tondanichthys kottelati'' – Vulnerable<ref>{{IUCN2006|assessors=World Conservation Monitoring Centre|id=21989|title=Tondanichthys kottelati|year=1996|downloaded=2007-02-10}}</ref> *''Zenarchopterus alleni'' – Data Deficient<ref>{{IUCN2006|assessors=Allen, G.|id=23202|title=Zenarchopterus alleni|year=1996|downloaded=2007-02-10}}</ref> *''Zenarchopterus robertsi'' – Lower Risk, Least Concern<ref>{{IUCN2006|assessors=Allen, G.|id=40694|title=Zenarchopterus robertsi|year=1996|downloaded=2007-02-10}}</ref> ==Images of halfbeaks== {{main|Gallery of beloniform fishes}} ==See also== * [[Live-bearing aquarium fish]] * [[USS Halfbeak (SS-352)]] American [[submarine]] named after these fish ==References== {{commonscat|Hemiramphidae}} {{wikispecies|Hemiramphidae}} <!-- ---------------------------------------------------------- See http://en.wikipedia.org/wiki/Wikipedia:Footnotes for a discussion of different citation methods and how to generate footnotes using the<ref>, </ref> and <reference /> tags ----------------------------------------------------------- --> {{reflist|2}} [[Category:Hemiramphidae| ]] [[Category:Ovoviviparous fish]] [[Category:Viviparous fish]] [[Category:Fishkeeping]] [[de:Halbschnäbler]] [[es:Hemiramphidae]] [[lt:Pusžiomenės vėjažuvės]] [[nl:Halfsnavelbekken]] [[ja:サヨリ]] [[pl:Półdziobcowate]] [[th:ปลาเข็ม]]