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Silver Needlefish

Handle with care

Tylosurus acus

Also known as: Agujon Needlefish, Houndfish, Atlantic Needlefish

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Description

Tylosurus acus, commonly known as the Silver Needlefish or Agujon Needlefish, is a large, predatory marine fish characterized by its extremely elongated, slender body and long, needle-like jaws. It is a pelagic species, often found near the surface in coastal and offshore waters. Its streamlined form and powerful tail make it an agile and fast swimmer, well-adapted for hunting other fish.

Physical Characteristics

Body shape
elongated
Coloration
Dorsal surface is typically dark blue to greenish-blue, fading to silvery on the sides and white on the belly. A prominent silvery lateral stripe may be present. Fins are generally dusky or translucent.
Scale type
cycloid
Mouth position
terminal
Distinctive features
Extremely elongated, slender body, Long, pointed jaws forming a 'needle-like' snout, with numerous sharp teeth, Dorsal and anal fins located far back on the body, nearly opposite each other, Large eyes, Absence of gill rakers on the first arch
Dorsal fin
Single dorsal fin, positioned posteriorly, with 21-25 soft rays. No spines.
Tail fin
Deeply forked caudal fin, with the lower lobe typically longer than the upper.
Pectoral fin
Relatively short pectoral fins, located low on the body.
Distinctive fins
Pelvic fins are small and abdominal, located far back on the body, well behind the pectoral fins.

Identification Tips

Body Shape and Jaws

The most striking feature is the very long, slender body and the extremely elongated, pointed jaws, which are characteristic of all needlefish. The jaws are filled with numerous sharp, conical teeth.

Fin Placement

Both the dorsal and anal fins are set far back on the body, almost directly opposite each other, close to the caudal peduncle. The caudal fin is deeply forked, with the lower lobe often longer.

Coloration

Look for the dark blue to greenish-blue back, silvery sides, and white belly. A distinct silvery lateral stripe may be present.

Size

Tylosurus acus is one of the larger needlefish species, reaching lengths of over 1 meter. This helps distinguish it from smaller, similar-looking species.

Habitat

Water type
saltwater
Depth
Primarily surface to 10 meters (33 feet), but can be found deeper in offshore waters.
Environment
Pelagic, inhabiting coastal and oceanic waters, often near reefs, sargassum beds, or floating debris. Also found in estuaries and brackish waters, particularly juveniles.
Geographic range
Circumglobal in tropical and subtropical waters. In the Atlantic, from Massachusetts (USA) to Brazil, including the Gulf of Mexico and Caribbean Sea; also eastern Atlantic from Senegal to Angola. In the Indo-Pacific, from the Red Sea and East Africa to the central Pacific, north to Japan and south to Australia.

Aquarium Information

  • Care level: expert
  • Temperament: aggressive
  • Diet: carnivore
  • Minimum tank size: 500 gallons
  • Temperature: 72-78°F (22-26°C)
  • pH level: 8.1-8.4
  • Hardness: 8-12 dKH
  • Compatibility: Only with very large, fast-moving, and equally aggressive fish that cannot be swallowed. Not suitable for most home aquariums due to size and predatory nature.
  • Special requirements: Requires a very large, long tank with ample swimming space. Excellent filtration and strong water movement are essential. Live food is often necessary to initiate feeding. Prone to injury from striking tank walls if startled.

Wild Information

  • Conservation status: least concern
  • Seasonality: Present year-round in tropical and subtropical waters, but may show seasonal movements related to prey availability or spawning.
  • Market price: Low to moderate, primarily for bait or local consumption.
  • Commercial importance: low
  • Taste: Mild, slightly fishy
  • Texture: Firm, white, flaky
  • Cooking methods: Frying, Grilling, Baking, Steaming
  • Nutritional value: Good source of lean protein, omega-3 fatty acids, and various vitamins and minerals. Bones can be numerous and fine.

Key Facts

Leaping Huntersbehavior

Needlefish are known for their remarkable ability to leap out of the water, often to escape predators or pursue prey. This behavior can be dangerous to humans, especially at night when they are attracted to lights and can impale individuals.

Ambush Predatorsbehavior

Despite their slender appearance, Silver Needlefish are formidable predators, using their speed and sharp jaws to ambush and capture smaller fish near the surface.

Ecological Roleinteresting

As apex predators in their near-surface habitat, Silver Needlefish play an important role in controlling populations of smaller pelagic fish, contributing to the balance of marine ecosystems.

Juvenile Jawsamazing

Interestingly, juvenile needlefish often have a shorter upper jaw than their lower jaw, which elongates as they mature to form the characteristic 'needle' snout.

Safety Information

Handle with care
  • Safety level: caution
  • Venomous: No
  • Edibility: edible
  • Handling notes: Needlefish, including Tylosurus acus, are not venomous. However, their sharp, pointed jaws and teeth can inflict painful wounds if handled carelessly. They are also known to leap out of the water and can cause injury to boaters or swimmers, especially at night when attracted to lights. Exercise caution when fishing for or handling these fish. Use appropriate tools like pliers for hook removal.

Similar Species

Flat Needlefish

Ablennes hians

Ablennes hians has a distinctly flattened body laterally, especially in the posterior half, and a series of vertical dark bars on its sides, which Tylosurus acus lacks. Its jaws are also shorter relative to its body length.

Houndfish

Tylosurus crocodilus

Tylosurus crocodilus is generally more robust and has a shorter, thicker snout compared to the more slender and longer-snouted Tylosurus acus. T. crocodilus also typically has a more pronounced dark blotch on the operculum (gill cover) and a more greenish coloration dorsally.

Atlantic Needlefish

Strongylura marina

Strongylura marina is a smaller species, rarely exceeding 60 cm. It has a more pronounced keeled caudal peduncle and often a more greenish-brown dorsal coloration. Its habitat often includes more estuarine and brackish environments than the predominantly marine Tylosurus acus.

Scientific Classification

Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Beloniformes
Family
Belonidae
Genus
Tylosurus
Species
Tylosurus acus

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