Depth range based on 20 specimens in 6 taxa.
Water temperature and chemistry ranges based on 12 samples.

Environmental ranges
  Depth range (m): 0 - 3530
  Temperature range (°C): 7.020 - 27.421
  Nitrate (umol/L): 0.286 - 8.857
  Salinity (PPS): 35.129 - 37.190
  Oxygen (ml/l): 4.682 - 6.192
  Phosphate (umol/l): 0.081 - 0.765
  Silicate (umol/l): 1.044 - 4.624

Graphical representation

Depth range (m): 0 - 3530

Temperature range (°C): 7.020 - 27.421

Nitrate (umol/L): 0.286 - 8.857

Salinity (PPS): 35.129 - 37.190

Oxygen (ml/l): 4.682 - 6.192

Phosphate (umol/l): 0.081 - 0.765

Silicate (umol/l): 1.044 - 4.624
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.


Article rating from 0 people

Default rating: 2.5 of 5

Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage

Barcode of Life Data Systems (BOLD) Stats
Specimen Records:1
Specimens with Sequences:0
Specimens with Barcodes:0
Species With Barcodes:0
Public Records:0
Public Species:
Public BINs:0
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)


Article rating from 0 people

Default rating: 2.5 of 5



Acentronura is a genus of pygmy pipehorse native to the Indian and Pacific oceans. The name is derived from the Greek ακεντρονουρα,[dubious ] or a-kentron-oura, and refers to the lack of a sting on the tail.[1]


There are currently two recognized species in this genus, several previous members having been moved to the genera Amphelikturus and Idiotropiscis:[2]

  • Acentronura gracilissima (Temminck & Schlegel, 1850) (Bastard seahorse)
  • Acentronura tentaculata (Günther, 1870) (Shortpouch pygmy pipehorse)


Acentronura species are mainly found in shallow tropical, subtropical waters of the Indo-west Pacific, Red Sea included.[3] When fully grown they vary from 5 to 8 centimetres (2.0 to 3.1 in) in length, The average maximal size is 6,3 cm.[4] They are small, secretive and very well camouflaged so although quite rarely seen; some species may be more common than they appear. Adults are usually found in the demersal region just above the substrate on the continental shelf, usually in water less than 20 metres (66 ft) deep. Juveniles are similar in form to the adults, but are pelagic and therefore may be found deeper than this.[1][5][6]


The Pygmy pipehorse, Acentronura tentaculata, showing the prehensile tail
The Pygmy pipehorse, Acentronura tentaculata, showing the cryptic colouration and overall appearance including the projections from the sides of the body

Adults may be found in or just above sandy or muddy substrates, around the base of macroalgae, especially red algae, or seagrass and close to or within coral reefs or rocky outcrops. Along with other members of the Syngnathidae family, they have protective bony or osseous armor plates covering their body surface. This limits their flexibility so that they tend to swim rather sluggishly with the body held horizontally, mainly using rapid fin movements. Like seahorses, their tail is prehensile and used for anchorage, winding itself around pieces of algae or seagrass.[1][6][7] However, the front part of the body is typical pipefish, with the head and body held in line rather than bent through and angle like seahorses. There is sexual dimorphism and the males are somewhat larger and more robustly built than the females. Because they are so small, the brood pouch is also large in proportion to the body, giving the males a somewhat more seahorse-like appearance than the females which have the typical slim linear form of pipefishes.[6]

Acentronura fish also have characteristically fused jaws like other members of the Syngnathidae. For those species where the feeding habits are known, the diet consists of small invertebrates such as planktonic crustacea which are snapped up by the small mouth at the tip of the snout, as they float past in the current.[1] With a slim snout, relatively large eyes and raised rear part of the skull, the head is somewhat reminiscent of that of a seahorse, in contrast to the short, slim body. There are often projections sticking out from the body and head at intervals along the length of the fish.[5][6]


Acentronura species are ovoviviparous so they give birth to live young. Like seahorses (Hippocampus spp.) and many other members of the Syngnathidae, the eggs are transferred at mating into a brood pouch on the ventral surface of the male. The brood pouch extends from just behind the anus to about halfway along the fairly short tail and is relatively large compared to the small size of the fish. It is formed by elongated folds of the skin surface which are less well protected by bony plates than the rest of the body. The eggs are incubated within individual skin cells in the brood pouch, hatch, and are released as their yolk sac is exhausted. .[1][7]

Acentronura tentacula is the best known of these species, but it is likely that other species have similar habits. These fish are most commonly seen in pairs, and this has led to the supposition that they are monogamous. However it is not known whether they do form long-lived pairs bonds or if these are quite changeable (as has recently been confirmed for some seahorse species, which were also assumed to be monogamous). In A. tentacula, the only species about which much is known, these new-born fish become free-swimming pelagic members of the plankton until they are part-grown, when they settle into their preferred adult habitat.[1][8]


  1. ^ a b c d e f "Shortpouch Pygmy Pipehorse Acentronura tentaculata Günther 1870, Fishes of Australia". Retrieved 2012-12-23. 
  2. ^ Froese, Rainer, and Daniel Pauly, eds. (2012). Species of Acentronura in FishBase. October 2012 version.
  3. ^
  4. ^
  5. ^ a b "Acentronura tentaculata Günther, 1870 Shortpouch pygmy pipehorse". Retrieved 2012-12-23. 
  6. ^ a b c d Kuiter, R.H. and T. Tonozuka (2001). Pictorial guide to Indonesian reef fishes. Part 1. Eels- Snappers, Muraenidae - Lutjanidae. Australia: Zoonetics. 
  7. ^ a b "Acentronura gracilissima(Temminck & Schlegel, 1850) Bastard seahorse Fishbase". Retrieved 2012-02-23. 
  8. ^ Breder, C. M. and D. E. Rosen (1966). Modes of reproduction in fishes. New Jersey: T.F.H. Publications. 
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia


Article rating from 0 people

Default rating: 2.5 of 5


EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!