Broadnosed pipefish

Broadnosed pipefish
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Syngnathiformes
Family: Syngnathidae
Subfamily: Syngnathinae
Genus: Syngnathus
Species: S. typhle
Binomial name
Syngnathus typhle
Linnaeus, 1758
Synonyms
  • Siphonostoma typhle (Linnaeus, 1758)
  • Siphostoma typhle (Linnaeus, 1758)
  • Syngnathus argentatus Pallas, 1814
  • Syngnathus pelagicus Risso, 1810
  • Syngnathus ponticus Pallas, 1814
  • Syngnathus pyrois Risso, 1827
  • Syngnathus rondeletii Delaroche, 1809
  • Syngnathus rotundatus Michahelles, 1829
  • Syngnathus thyphle Linnaeus, 1758
  • Syngnathus viridis Risso, 1810
  • Syphonostoma typhle (Linnaeus, 1758)
  • Tiphle hexagonus Rafinesque, 1810

Broadnosed pipefish (Syngnathus typhle) is a fish of the Syngnathidae family (seahorses and pipefishes). It is native to the Eastern Atlantic from Vardø in Norway, Baltic Sea (north to the Gulf of Finland) and the British Isles at North to Morocco at South. Also in the Mediterranean Sea, Black Sea and Sea of Azov. It is common in the coastal shallow waters, usually on reefs with seagrasses. This species is notable for its "broad" snout, which is as deep as its body.

Description

The broadnosed pipefish is a slender, elongated fish with a hexagonal cross-section which distinguishes it from its even more threadlike relation the straightnose pipefish (Nerophis ophidion) which has a circular cross-section. The body surface is covered by small bony plates. The head resembles that of a seahorse with a long, laterally flattened snout and obliquely sloping mouth. Unlike the straightnose pipefish, it has a fan-shaped caudal fin. The general colour is greenish, often with various darker mottling, and the belly is yellow. The average size is about 15 to 20 cm (6 to 8 in) with a maximum of 25 cm (10 in).[2]

Distribution

The broadnosed pipefish is native to the Eastern Atlantic, the Mediterranean Sea, the Black Sea and the Sea of Azov. Its range extends from Vardø, Norway to Morocco. It is found at depths down to about 20 m (66 ft).[3]

Biology

The broadnosed pipefish tends to rest in a vertical position among the fronds of seaweed and feeds on plankton such as copepods which it sucks in through its mouth.[2]

This species of pipefish has a sex-role reversed mating system in which females compete for access to males.[4] This fish breeds in the summer. The male has a brood pouch into which several females deposit clutches of about twenty eggs and where the eggs are fertilised. The fry hatch after about four weeks and are expelled into the open water. Even after this the male continues to provide some parental care as the fry can retreat into the brood pouch in case of danger.[2]

Reproduction

Courtship and copulation

Males and females both actively court one another for mating, but courting is more frequent in females. [5] Courtship and copulation follow a stereotyped pattern, beginning when one fish identifies a prospective mate nearby and performs the ritualized dance. [6] If the other is receptive, the two align and continue the dance together until the female delivers her eggs into the male's brood pouch via an ovipositor. [6][7] The male then shakes the eggs into his brood pouch, releases his sperm into the pouch and assumes an S-shaped posture to fertilize the eggs. [6]

Mating system

These pipefish have a polygynandrous mating system, with both males and females mating with multiple partners during a breeding season. [8]

 

Like other species of pipefish, the broadnosed pipefish is sex-role reversed: males brood the eggs and because of their increased investment in offspring are the choosier sex, whereas females compete more intensely than males for access to mates. [5] Females can produce eggs faster than males can brood them, and are limited by the size of the male's brood pouch, which cannot carry all the eggs of a female similar to himself in size. [9] [10] Male brood time is approximately four to six weeks, during which time the male provides oxygen and nutrients to the developing embryos until they hatch. [10] [11] One to six females contribute to each brood clutch, which is the highest rate of multiple maternity in all of the pipefish species. [8]

Mate choice

Although males are choosier than females, both sexes exhibit a preference for large mates due to a positive correlation between size and fecundity. [12][9] Large females produce more and larger eggs and transfer more eggs per mating, while large males have increased brood clutch size and embryo weight. [7] Males also exhibit an avoidance of females carrying high parasite loads, which is negatively correlated with fecundity. [13]

The pipefish are not always able to mate with their preferred mates. For example, when predators are present, males are less choosy and mate indiscriminately with small and large females. [14] However, both sexes can compensate for mating with non-preferred mates. For example, females deposit more proteinaceous eggs when mating with a lower quality male. [9]  This increases offspring viability since the smaller males are less able to nurture the embryos himself. [9] Males, on the other hand, can selectively absorb the eggs of lower-quality females after copulation. [15] By doing so, the male gains nutrients by ingesting the nutritious egg, which he can then allocate to caring for the embryos he sires with preferred, higher quality females in the future. [15]

References

  1. ↑ NatureServe (2013). "Syngnathus typhle". IUCN Red List of Threatened Species. Version 2014.3. International Union for Conservation of Nature. Retrieved 15 December 2014.
  2. 1 2 3 "Broad-nosed pipefish: Syngnathus typhle (L.)". NatureGate. Retrieved 2013-12-19.
  3. ↑ "Syngnathus typhle Linnaeus, 1758: Broadnosed pipefish". FishBase. Retrieved 2013-12-19.
  4. ↑ Berglund, Anders (2003). "Sex role reversal in pipefish". Advances in the Study of Behavior. 32: 131–167.
  5. 1 2 Anders, Berglund; Widemo, Maria; Rosenqvist, Gunilla (2005). "Sex-role reversal revisited: choosy females and ornamented, competitive males in a pipefish" (PDF). Behavioral Ecology. 16: 649–655.
  6. 1 2 3 Dugatkin, Lee. "Pipefish Courtship and Copulation". W. W. Norton & Company.
  7. 1 2 Berglund, Anders; Rosenqvist, Gunilla; Svensson, Ingrid (1988). "Multiple Matings and Paternal Brood Care in the Pipefish Syngnathus typhle". Oikos. 51: 184–188 – via JSTOR.
  8. 1 2 Jones, Adam; Rosenqvist, Gunilla; Berglund, Anders; Avise, John (1999). "The Genetic Mating System of a Sex-Role-Reversed Pipefish (Syngnathus typhle): A Molecular Inquiry". Behavioral Ecology and Sociobiology. 46: 357–365 – via JSTOR.
  9. 1 2 3 4 Goncalves, Ines; Mobley, Kenyon; Ahnesjö, Ingrid; Sagebakken, Gry; Jones, Adam; Kvarnemo, Charlotta (2010). "Reproductive compensation in broad-nosed pipefish females". Royal Proceedings: Biological Sciences. 277: 1581–1587 – via JSTOR.
  10. 1 2 Berglund, Anders; Rosenqvist, Gunilla (1990). "Male Limitation of Female Reproductive Success in a Pipefish: Effects of Body-Size Differences". Behavioral Ecology and Sociobiology. 27: 129–133 – via JSTOR.
  11. ↑ Ahnesjö, Ingrid (1996). "Apparent Resource Competition among Embryos in the Brood Pouch of a Male Pipefish". Behavioral Ecology and Sociobiology. 38: 167–172 – via JSTOR.
  12. ↑ Bernet, Patricia; Rosenqvist, Gunilla; Berglund, Anders (1998). "Female-Female Competition Affects Female Ornamentation in the Sex-Role Reversed Pipefish Syngnathus typhle". Behaviour. 5: 535–550 – via JSTOR.
  13. ↑ Rosenqvist, Gunilla; Johansson, Kerstin (1995). "Male avoidance of parasitized females explained by direct benefits in a pipefish". Animal Behaviour. 49: 1039–1045.
  14. ↑ Berglund, Anders (1993). "Risky sex: male pipefishes mate at random in the presence of a predator". Animal Behaviour. 46: 169–175.
  15. 1 2 Berglund, Anders (18 March 2010). "Evolutionary biology: Pregnant fathers in charge". Nature.
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