Abstract
To the Editor:
Fish belonging to the Belonidae family have a geographic distribution in tropical and subtropical regions in the Atlantic, Pacific, and Indian Oceans. Some species of belonids are found in freshwater environments, in the hydrographic basins of South and Central America, Australia, and Asia. 1 The marine species of Belonidae are pelagic, found in oceanic areas and in coastal regions, especially young fish, which can be found in shallow environments such as inlets and regions between tides. 2 These fish have remarkable characteristics, such as a long and narrow body and extended upper and lower jaws forming a bony blade with numerous teeth projected in front of the head (Figure 1). Some specimens can reach considerable sizes, over 100 cm in length. 2
Needlefish of the Belonidae family. Note the long jaws with pointed teeth. Photography: Vidal Haddad Junior.
Most species of belonid fish (or needlefish), especially juvenile fish, form large schools swimming at or near the surface. 2 The formation of schools of juvenile fish at the surface of the oceans is accompanied by different behaviors, both in terms of attraction and escape. Adult and young Belonidae fish have positive phototactism and are attracted by light, swimming at great speed and jumping out of the water toward the light source. Escape behavior also triggers the habit of speeding up and jumping out of the water; this behavior is stimulated by the presence of predators or by any disturbance on the surface of the water close to the school, which may represent a danger, such as the presence of floating objects such as surfboards or small boats. 3 These behaviors, both attraction to light and escape, have caused numerous accidents with humans for decades, both by fishing with luminous attraction and by escape behavior. 4 –8
A 20-y-old male sought care at the emergency unit of Guarujá town, in the north coast of São Paulo State, Brazil. He reported pain in his left ear after feeling a sting while surfing on one of the beaches of the region. The patient was healthy, with no history of pre-existing disease or routine use of medications.
On physical examination, the patient had a foreign body perforating the region posterior to the left auricular pavilion to the shell (Figure 2). Otoscopy was performed, and no foreign body was observed in the middle ear, implying that it had only reached the subcutaneous region. A radiologic examination did not show any perforations or other bone lesions. The foreign body was removed after antisepsis with alcoholic chlorhexidine. Local anesthesia was performed with 2 mL of 2% lidocaine in the region close to the perforation (posterior side of the left external ear shell). With use of straight Kelly clamps, the foreign body was removed without any complications. The foreign body was a pointed fish jaw, about 3 cm, and was identified by an author ichthyologist as the mandible of a needlefish (Figures 3 and 4). The perforation had a diameter of approximately 3 cm, and the wound was left open with a dressing. Cephalexin was administered at a dosage of 500 mg orally every 6 h for 5 d, and the patient returned for follow-up without complications after 1 wk.
Patient with a foreign body perforating the region posterior to the left auricular pavilion. Photography: Lauro Ferreira Gonçalves.
Fragments of the jaw of a needlefish extracted from the victim, measuring about 1.5 cm. Photography: Lauro Ferreira Gonçalves.
Detail of the extracted fragment. Photography: Lauro Ferreira Gonçalves.
Needlefish have a wide distribution, and their habit of moving in schools close to the surface and jumping in bright spots or during movement predisposes them to incidents with humans. 4 –8 Although most accidents happen to fishermen on boats with light sources, shoals have the potential to cause serious injuries to victims who practice sports such as surfing, windsurfing, and swimming. The injuries can be serious, and health care teams must be aware of the possibility of an incident with needlefish when foreign bodies are found in patients; the jaw of these fish has a typical aspect and is usually the part found at the point of perforation.
Therapeutic measures consist of extracting the fragment and using systemic antibiotics, remembering that occasionally there may be permanence of fragments and perforation of vital human body structures such as the eyes and thoracic and abdominal organs and that certain species of needlefish can reach 1 m in length, with “beaks” of more than 30 cm.