• Source: Nomorhamphus

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 (0.39 to 0.59 in) 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 (often having red, black, or blue patches on their fins). 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 (e.g., N. ebrardtii) have short, straight beaks, but those of others (e.g., N. liemi) 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.
Nomorhamphus feed extensively on small insects, either in the form of aquatic larvae or as flying insects that have fallen onto the surface of the water. They are important predators on insects such as mosquitoes, so play a role in controlling malaria. Nomorhamphus are too small to be of value as food, but they do have some value as aquarium fish.




Reproduction



Nomorhamphus species are livebearing fish that practise internal fertilisation. The male is equipped with a gonopodium-like anal fin known as a gonopodium that delivers sperm into the female. The gestation period is about six weeks. The exact mode of reproduction ranges from ovoviviparity through to viviparity, and in some species, oophagy is known, as well. Only around ten to twenty embryos are developed at a time, but at birth these are fairly large (around 13 millimetres or 0.5 inches) and well developed, able to take small prey, such as Daphnia, immediately after birth.




Species


There are currently 22 recognized species in this genus:

Nomorhamphus aenigma Kobayashi, Masengi & Yamahira, 2020
Nomorhamphus bakeri Fowler & B. A. Bean, 1922
Nomorhamphus brembachi D. Vogt, 1978
Nomorhamphus celebensis M. C. W. Weber & de Beaufort, 1922 (Poso halfbeak)
Nomorhamphus ebrardtii Popta, 1912
Nomorhamphus hageni Popta, 1912
Nomorhamphus kolonodalensis A. D. Meisner & Louie, 2000
Nomorhamphus lanceolatus Huylebrouck, Hadiaty & Herder, 2014
Nomorhamphus liemi D. Vogt, 1978
Nomorhamphus manifesta A. D. Meisner, 2001
Nomorhamphus megarrhamphus Brembach, 1982
Nomorhamphus pectoralis Fowler, 1934
Nomorhamphus philippina Ladiges, 1972
Nomorhamphus pinnimaculatus A. D. Meisner, 2001
Nomorhamphus ravnaki Brembach, 1991
Nomorhamphus rex Huylebrouck, Hadiaty & Herder, 2012
Nomorhamphus rossi A. D. Meisner, 2001
Nomorhamphus sagittarius Huylebrouck, Hadiaty & Herder, 2014
Nomorhamphus sanussii Brembach, 1991
Nomorhamphus towoetii Ladiges, 1972
Nomorhamphus vivipara W. K. H. Peters, 1865
Nomorhamphus weberi Boulenger, 1897




References






Further reading


Scott, Peter (1997): Livebearing Fishes, Tetra Press, ISBN 1-56465-193-2

Kata Kunci Pencarian:

• Julung-julung Poso
• Danau Poso
• Julung-julung
• Julung-julung vivipar
• Daftar nama ikan air tawar endemik Indonesia
• Sungai Maros
• Flora dan Fauna di Kabupaten Maros
• Nomorhamphus
• Nomorhamphus aenigma
• Nomorhamphus megarrhamphus
• Nomorhamphus ebrardtii
• Nomorhamphus weberi
• Sulawesi
• Zenarchopteridae
• Nomorhamphus towoetii
• Poso halfbeak
• Yolk