Nomorhamphus
Encyclopedia
The freshwater
halfbeak
s of the genus Nomorhamphus are widely distributed in Southeast Asia
, in particular the islands of the Philippines, Indonesia, and Sulawesi. 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 are about 100 mm in length, whereas the males are about 60 to 70 mm 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.
Nomorhamphus fish feed extensively on small insects, either in the form of aquatic larva
e 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 fish are too small to be of value as food, but they do have some value as aquarium fish
.
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 (see section on reproduction in the halfbeak article). Only around ten to twenty embryos are developed at a time, but at birth these are fairly large (around 13 mm) and well developed, able to take small prey, such as Daphnia
, immediately after birth.
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
halfbeak
Halfbeak
The halfbeaks are a geographically widespread and numerically abundant family of epipelagic fish inhabiting warm waters around the world. The family Hemiramphidae is divided into two subfamilies, the primarily marine Hemiramphinae and the freshwater or estuarine Zenarchopterinae...
s of the genus Nomorhamphus are widely distributed in Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
, in particular the islands of the Philippines, Indonesia, and Sulawesi. 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 are about 100 mm in length, whereas the males are about 60 to 70 mm 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
Mandible
The mandible pronunciation or inferior maxillary bone forms the lower jaw and holds the lower teeth in place...
, 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
Goatee
Goatee refers to a style of facial hair incorporating hair on a man’s chin. The exact nature of the style has varied according to time and culture.Traditionally, goatee refers solely to a beard formed by a tuft of hair on the chin...
beard by aquarists.
Nomorhamphus fish feed extensively on small insects, either in the form of aquatic larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e 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
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
. Nomorhamphus fish are too small to be of value as food, but they do have some value as aquarium fish
Halfbeak
The halfbeaks are a geographically widespread and numerically abundant family of epipelagic fish inhabiting warm waters around the world. The family Hemiramphidae is divided into two subfamilies, the primarily marine Hemiramphinae and the freshwater or estuarine Zenarchopterinae...
.
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 gestationGestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
period is about six weeks. The exact mode of reproduction ranges from ovoviviparity through to viviparity, and in some species, oophagy
Oophagy
Oophagy , literally "egg eating", is the practice of embryos feeding on eggs produced by the ovary while still inside the mother's uterus. The word oophagy is formed from the classical Greek ᾠόν and classical Greek φᾱγεῖν ....
is known, as well (see section on reproduction in the halfbeak article). Only around ten to twenty embryos are developed at a time, but at birth these are fairly large (around 13 mm) and well developed, able to take small prey, such as Daphnia
Daphnia
Daphnia are small, planktonic crustaceans, between 0.2 and 5 mm in length. Daphnia are members of the order Cladocera, and are one of the several small aquatic crustaceans commonly called water fleas because of their saltatory swimming style...
, immediately after birth.
Species
- Nomorhamphus australis
- Nomorhamphus bakeri
- Nomorhamphus brembachi
- Nomorhamphus celebensis
- Nomorhamphus hageni
- Nomorhamphus kolonodalensis
- Nomorhamphus liemi
- Nomorhamphus manifesta
- Nomorhamphus megarrhamphus
- Nomorhamphus pectoralis
- Nomorhamphus philippina
- Nomorhamphus pinnimaculata
- Nomorhamphus ravnaki
- Nomorhamphus rossi
- Nomorhamphus sanussii
- Nomorhamphus towoetii
- Nomorhamphus vivipara
- Nomorhamphus weberi