Zenarchopteridae

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Zenarchopteridae
Dermogenys sumatrana 02.jpg
Female Dermogenys sumatrana a day or so before giving birth.
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Beloniformes
Superfamily: Exocoetoidea
Family: Zenarchopteridae
Fowler, 1934
Genera [1]

See text

Zenarchopteridae, the viviparous halfbeaks, is a family in the order Beloniformes. The Zenarchopteridae exhibit strong sexual dimorphism, practicing internal fertilisation, and in some cases ovoviviparous or viviparous (the family also includes oviparous species). [2] [3] The members in the family are mainly found in fresh and brackish water of tropical Asia and New Guinea, but the genus Zenarchopterus also includes marine species from the Indo-Pacific. Several, such as the wrestling halfbeak, have become commonly traded aquarium fish. [4]

Contents

Genera

The following genera are classified within the family Zenarchopteridae [5]

Behaviour

Viviparous halfbeaks vary in social behavior from open water schooling fish similar to the marine halfbeaks (family Hemiramphidae), as with species of Zenarchopterus , [6] through to much more aggressive and combative fishes, as is best known from the "wrestling" halfbeaks of genus Dermogenys . [7] These non-schoolers prefer to lurk among aquatic plants such as reeds, dead trees, and artificial structures of various types; from where they wait for small prey animals to drift by or alight on the surface, before darting from their hiding place to hunt. [8] Notably, they 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. [8]

Feeding

Viviparous halfbeaks are more predatory than the marine species, and typically orient themselves into the current and take aquatic insect larvae, such as midge larvae, and small insects, such as flies that have fallen on the surface of the water, particularly mosquitoes and spiders. [8] [9] [10]

Breeding

Young fresh water halfbeak, Nomorhamphus sp., aged 7 days, approximately 18 mm (0.71 in) in length. Captive bred specimen. Halfbeak fry.jpeg
Young fresh water halfbeak, Nomorhamphus sp., aged 7 days, approximately 18 mm (0.71 in) in length. Captive bred specimen.

Members of the genus Zenarchopterus and presumably the poorly-known Tondanichthys are oviparous. [2]

The fresh and brackish water halfbeaks of the genera Dermogenys, Hemirhamphodon, and Nomorhamphus are all livebearers (with the exception of the oviparous H. tengah [3] ), that is, they 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 viviparity and ovoviviparity in fresh and brackish water halfbeaks: [11]

TypeEgg location Superfetation (sperm storage)Yolk sacMaternal connection Broods per matingExampleNotes
1 ovarian follicle NoLargeNone- Southeast Asian populations of Dermogenys pusilla
2 ovarian follicle YesSmallvia the coelomic cavity and pericardial sac 3Dermogenys pusilla from Sabah and Dermogenys orientalis
3 ovarian follicle, briefly, then along full ovary lengthYesSmallVia expanded belly sac2Dermogenys viviparus
4 ovarian follicle, briefly, then along full ovary lengthNoLargeNoNomorhamphus megarrhamphus, Nomorhamphus weberi, and Nomorhamphus towoetii
5 ovarian follicle, briefly, then along full ovary lengthYesSmallPartialNomorhamphus ebrardtiiLate-stage embryos are oophagous (eating eggs and small embryos) [11] like sharks and a few other fishes.

As with other livebearing fish, fresh and brackish water halfbeaks produce small broods of large offspring compared with egg-laying species of similar size, with broods of around ten to twenty, typically 10–15 millimeters (0.39–0.59 in) long. [12]

Sexual dimorphism

Hemirhamphodon pogonognathus with key morphological features labelled; note the great length of the lower jaw compared with the upper jaw. Labelled H pogonognathus.jpg
Hemirhamphodon pogonognathus with key morphological features labelled; note the great length of the lower jaw compared with the upper jaw.

Sexual dimorphism is apparent in some species. Males of the ovoviviparous and viviparous species all have a modified anal fin, the andropodium , similar to the gonopodium of poecilid livebearers, used to deliver sperm to the females. [8] Although most egg laying species mate by shedding the milt externally, as is typical for bony fish, at least some practice internal fertilization: male Zenarchopterus use a modified anal fin to direct sperm into the genital opening of the female prior to spawning. [13]

Besides modifications to the anal fin, other differences include size, coloration, and the beak's length or shape. Female Normorhamphus are much larger than males but aren't as brightly colored and have shorter beaks. [14] By contrast, male Hemirhamphodon are larger than females, and some species, such as Hemirhamphodon pogonognathus, also have a long beard-like tassel on the end of the beak. [15] Small colored patches, particularly among males, are only found on the fins and the tip of the beak. [14]

Gambling

They are small and generally peaceful towards other species, although males can be aggressive to one another. [12] Dermogenys pusillius, the wrestling halfbeak, in particular fight vigorously. Battles may end in injuries. In some Asian countries gamblers bet on the outcomes, as they do with Siamese fighting fish. [7] [16]

In the aquarium

Nomorhamphus liemi liemi halfbeaks ready for introduction to a new aquarium. N liemi bagged.JPG
Nomorhamphus liemi liemi halfbeaks ready for introduction to a new aquarium.

Some of the fresh and brackish water species are kept as ornamental aquarium fish, [17] particularly genera Dermogenys and Nomorhamphus, but also Hemirhamphodon and Zenarchopterus, less commonly. [6] [15] [18] [19]

To be kept successfully, halfbeaks require an aquarium with plenty of space at the surface. Depth is not critical, so a wide tank is better than a deep one. They are sensitive to low oxygen levels but are otherwise relatively hardy, except that they are intolerant of sudden changes in salinity, pH, hardness, or temperature. Consequently, they must be introduced to a new aquarium gently, and small but frequent water changes are best, so the water chemistry does not change suddenly. [20] A few species, most notably Dermogenys pusillius, have traditionally been kept in slightly brackish water, though some authors aver that those found in brackish water are estuarine juveniles. [6] [17] Most traded species of Nomorhamphus and Hemirhamphodon prefer soft, neutral to slightly acidic, fresh water conditions. [12] [21]

Halfbeaks are sensitive and shocks like sudden changes in illumination can evoke frantic swimming activity. They may crash into the glass, injuring their beaks, or jump out of the tank. Such beak injuries usually heal within a few weeks. They will eat insect larvae such as bloodworms readily, as well as crustacean eggs, shrimp, fruit flies, and 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 plant food probably suits them. [22]

Halfbeaks breed in captivity, but despite being livebearers not easily. [12] Miscarriages are common, particularly if the females are stressed (for example, by being moved to another aquarium). Once the fry have been born, the large babies eat newly hatched brine shrimp, small live foods such as daphnia, and powdered flake. [23]

Conservation status

A number of fresh water halfbeaks are listed in various categories on the IUCN Red List assessing 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. Several species are listed as Data Deficient (and many have not been rated at all), meaning that their present status is unclear based on available information.

Related Research Articles

Hemiramphidae is a family of fishes that are commonly called halfbeaks, spipe fish or spipefish. They are a geographically widespread and numerically abundant family of epipelagic fish inhabiting warm waters around the world. The halfbeaks are named for their distinctive jaws, in which the lower jaws are significantly longer than the upper jaws. The similar viviparous halfbeaks have often been included in this family.

<span class="mw-page-title-main">Beloniformes</span> Order of fishes

Beloniformes is an order composed of six families of freshwater and marine ray-finned fish:

<span class="mw-page-title-main">Wrestling halfbeak</span> Species of fish

The wrestling halfbeak also known as Malayan halfbeak is a species of viviparous halfbeak native to the fresh and brackish waters of rivers and coastal regions in South-East Asia, in Singapore, Thailand, Indonesia, Thailand, Malaysia, Borneo and Sumatra. It is a small, slender, livebearing fish, with the elongated lower jaw characteristic of its family. The colour of this species varies, depending on where the specimen is found. It is the type species of the genus Dermogenys.

The ballyhoo halfbeak or ballyhoo is a baitfish of the halfbeak family (Hemiramphidae). It is similar to the Balao halfbeak in most features. Ballyhoo are frequently used as cut bait and for trolling purposes by saltwater sportsmen. The fish is reported to have caused ciguatera poisoning in humans.

<i>Nomorhamphus</i> Genus of fishes

Nomorhamphus is a southeast Asian genus of viviparous halfbeaks from streams, rivers and lakes in Sulawesi (Indonesia) and the Philippines. They are all viviparous, producing small clutches of around a dozen fry about 10 to 15 mm long at birth. Females are generally larger than the males. In the largest species, such as Nomorhamphus liemi, the females typically reach about 10 centimetres (3.9 in) in length, whereas the males reach about 6–7 cm (2.4–2.8 in) in length. Males are also more brightly coloured than the females. Compared with many other halfbeaks, the lower mandible, or beak, is relatively short, on females in particular barely protruding beyond the length of the upper mandible. The males of some species have short, straight beaks, but those of others have short beaks that curve downwards forming a shape often compared to a goatee beard by aquarists. N. aenigma is unique within Nomorhamphus because of its lack of lower jaw elongation.

<i>Dermogenys</i> Genus of fishes

Dermogenys is a genus of viviparous halfbeaks. They are widely distributed in fresh and brackish water in South and Southeast Asia, ranging from India to the Philippines and Greater Sundas. They are all viviparous, producing small clutches of up to 30 fry that closely resemble the adults, except they are much smaller, around 1–1.5 cm (0.4–0.6 in) in length. Adults are typically around 6–7 cm (2.4–2.8 in) in length, with females being slightly larger than males. Males tend to be more brightly coloured and are well known for being aggressive towards one another. The wrestling halfbeak, D. pusilla, is widely used in Asia as fighting animals upon which wagers are placed. Both sexes have lower jaws (mandibles) that are much longer than the upper ones, and from this comes the "halfbeak" name.

<i>Xenentodon cancila</i> Species of fish

Xenentodon cancila, the freshwater garfish, is a species of needlefish found in freshwater and brackish habitats in South and Southeast Asia.

Nomorhamphus megarrhamphus is a species of viviparous halfbeak, a freshwater fish endemic to Lake Towuti in Sulawesi, Indonesia.

Nomorhamphus weberi is a species of viviparous halfbeak endemic to Lake Matano in Sulawesi, Indonesia. This species can reach a length of 7.5 centimetres (3.0 in) SL. The specific name honours the Dutch ichthyologist Max Carl Wilhelm Weber (1852-1937).

The Poso halfbeak is a species of viviparous halfbeak endemic to Lake Poso and its tributaries in Sulawesi, Indonesia.

Nomorhamphus towoetii is a species of fish in the family Hemiramphidae.

Tondanichthys kottelati is a species of viviparous halfbeak endemic to Indonesia, where it is only known from Lake Tondano near Mount Tondano in the far north of the island of Sulawesi. It grows to a length of 6.4 centimetres (2.5 in) SL. Despite being a member of the viviparous halfbeak family, this species is believed to be oviparous. This species was described in 1995 by Bruce Baden Collette and its species name honours the Swiss ichthyologist Maurice Kottelat.

Allen's river garfish is a species of viviparous halfbeak endemic to West Papua in Indonesia.

<i>Zenarchopterus</i> Genus of fishes

Zenarchopterus is a genus of viviparous halfbeaks. These fish are found in marine, brackish and fresh water of the Indo-Pacific region. Despite being in the viviparous halfbeak family, Zenarchopterus species are oviparous.

Robert's river garfish is a species of viviparous halfbeak endemic to Papua New Guinea where it is only known from the area around Kokoda. This species grows to a length of 13 centimetres (5.1 in) SL.

The Congaturi halfbeak, also known as the Valenciennes halfbeak, is a potamodromous species of fish in the family Hemiramphidae. It is a valued commercial fish in tropical countries both dried salted and fresh forms.

The feathered river garfish, also known as the estuarine halfbeak, spoon-fin garfish, spoon-fin river garfish and viviparous half beak, is a species of marine, freshwater, brackish and reef-associated oceanodromous viviparous halfbeak found in Indo-Pacific regional countries, such as Kenya, Mozambique, Seychelles, Madagascar, New Guinea, Solomon Islands, Australia, New Caledonia, Fiji, Sri Lanka, India, Vanuatu, Malaysia, Thailand, Singapore and Samoa.

<i>Poeciliopsis prolifica</i> Species of fish

Poeciliopsis prolifica, or the blackstripe livebearer, is a species of small freshwater fish in the family Poeciliidae. It is endemic to Mexico. It is a viviparous species and the female can have several clutches of young developing internally at the same time, hence the specific name prolifica, from the Latin proles, "offspring" and ferax, "rich, fruitful" in reference to the great number of young produced.

<i>Nomorhamphus ebrardtii</i> Species of fish

Nomorhamphus ebrardtii is a species of viviparous halfbeak, a ray-finned fish in the family Zenarchopteridae, endemic to brackish and freshwater locations in Sulawesi and the neighbouring island of Kabaena in Indonesia. This species can reach a length of 9 cm (3.5 in) SL.

Dermogenys brachynotopterus, the Gangetic halfbeak, is a species of viviparous halfbeak.

References

  1. ↑ Froese, Rainer, and Daniel Pauly, eds. (2013). "Zenarchopteridae" in FishBase. June 2013 version.
  2. 1 2 Berra, T.M. (2001). Freshwater Fish Distribution. p. 320. ISBN   978-0-12-093156-9
  3. 1 2 Tan, H.H. & Lim, K.K.P. (2013). Three new species of freshwater halfbeaks (Teleostei: Zenarchopteridae: Hemirhamphodon) from Borneo. The Raffles Bulletin of Zoology 61(2): 735–747.
  4. ↑ Collette, Bruce B. (February 2004). "Family Hemiramphidae Gill 1859 – Halfbeaks" (PDF). California Academy of Sciences Annotated Checklist of Fishes.
  5. ↑ Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Genera in the family Zenarchopteridae". Catalog of Fishes . California Academy of Sciences . Retrieved 23 August 2019.
  6. 1 2 3 Schäfer, Frank (2005). Brackish Water Fishes. Aqualog. ISBN   3-936027-82-X.
  7. 1 2 Sterba, G (1962). Freshwater Fishes of the World. Vista Books. p. 609.
  8. 1 2 3 4 Hoedeman, J. (1974). Naturalist's Guide to Freshwater Aquarium Fish. Elsevier. pp. 724–729. ISBN   0-8069-3722-X.
  9. ↑ "Forest Halfbeak". EcologyAsia. Archived from the original on May 7, 2006. Retrieved 2006-09-03.
  10. ↑ "Pygmy Halfbeak". EcologyAsia. Archived from the original on May 7, 2006. Retrieved 2006-09-03.
  11. 1 2 Meisner, A; Burns, J (1997). "Viviparity in the Halfbeak Genera Dermogenys and Nomorhamphus (Teleostei: Hemiramphidae)". Journal of Morphology. 234 (3): 295–317. doi:10.1002/(SICI)1097-4687(199712)234:3<295::AID-JMOR7>3.0.CO;2-8. PMID   29852651.
  12. 1 2 3 4 "Keeping & Breeding Halfbeaks" . Retrieved 2006-09-03.
  13. ↑ Kottelat, M; Lim, K (1999). "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)". Copeia . 1999 (4): 1097–1101. doi:10.2307/1447985. JSTOR   1447985.
  14. 1 2 Riehl, R; Baensch, H (1996). Aquarium Atlas. Vol. 1. Voyageur Press. ISBN   3-88244-050-3.
  15. 1 2 Riehl, R; Baensch, H (1997). Aquarium Atlas. Vol. 2. Microcosm Ltd. ISBN   1-890087-06-8.
  16. ↑ "Freshwater Fishes and the Singaporean" . Retrieved 2007-01-25.
  17. 1 2 Monks, Neale, ed. (2006). "Brackish Water Fishes". Tropical Fish Hobbyist . Neptune City, N.J.: T.F.H. ISBN   0-7938-0564-3.
  18. ↑ Schäfer, F; Kemkes, M. (1998). All Livebearers and Halfbeaks. Aqualog. ISBN   3-931702-77-4.
  19. ↑ Dawes, J (1995). Livebearing Fishes: A Guide To Their Aquarium Care, Biology and Classification . Blandford. ISBN   0-7137-2592-3.
  20. ↑ Fischer, Roger (January–February 1994). "Halfbeaks". Aqua News. Archived from the original on October 11, 2007. Retrieved 2006-09-03.
  21. ↑ Monks, Neale (November 2006). "Life at the Top". Tropical Fish Hobbyist .
  22. ↑ Monks, Neale (October 2005). "Straight to the point: the Beloniformes". Practical Fishkeeping.
  23. ↑ Blewett, Earl. "Dermogenys pusillus - The Wrestling Halfbeak Livebearer" (PDF). Retrieved 2006-09-03.
  24. ↑ IUCN (2018-06-13). "Nomorhamphus megarrhamphus: Lumbantobing, D.: The IUCN Red List of Threatened Species 2019: e.T90981984A90981998". doi: 10.2305/iucn.uk.2019-2.rlts.t90981984a90981998.en .
  25. ↑ IUCN (2018-06-29). "Nomorhamphus weberi: Lumbantobing, D.: The IUCN Red List of Threatened Species 2019: e.T90982032A90982071". doi: 10.2305/iucn.uk.2019-2.rlts.t90982032a90982071.en .
  26. ↑ IUCN (2019-01-22). "Nomorhamphus celebensis: Mokodongan, D.F.: The IUCN Red List of Threatened Species 2019: e.T40693A90981218". doi: 10.2305/iucn.uk.2019-2.rlts.t40693a90981218.en .
  27. ↑ Lumbantobing, D. (2019). "Nomorhamphus towoetii". IUCN Red List of Threatened Species . 2019: e.T169525A90981252. doi: 10.2305/IUCN.UK.2019-2.RLTS.T169525A90981252.en .
  28. ↑ IUCN (2020-01-17). "Tondanichthys kottelati: Daniels, A.: The IUCN Red List of Threatened Species 2020: e.T21989A90982079". doi: 10.2305/iucn.uk.2020-3.rlts.t21989a90982079.en .
  29. ↑ IUCN (2020-05-21). "Zenarchopterus alleni: Palmer-Newton, A.: The IUCN Red List of Threatened Species 2020: e.T23202A127950613". doi: 10.2305/iucn.uk.2020-3.rlts.t23202a127950613.en .
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