Longspine snipefish

Longspine snipefish are reddish pink dorsally but have silvery bellies. They have a large eye, long snouts, and a slender spine protruding dorsally. A prominent feature of the longspine snipefish is their second spine in the first dorsal fin, which ranges from 21.92 mm to 36.47 mm. Males exhibit a slightly shorter postocular head length compared to females. Planktivorous fish have relatively longer snouts, slender bodies, shorter second dorsal spines, and smaller eyes, whereas benthic-feeding fish have shorter snouts, deeper bodies, longer dorsal spines, and larger eyes. Although the studies used different type names, the gracilis type aligns with the planktivorous type and the scolopax type with the benthic feeding type, representing a deeper-bodied form with longer spines. The study also rejected the hypothesis that the gracilis type may represent a juvenile stage of the scolopax type, as gracilis specimens were larger than scolopax specimens in this study. ==Biology==

The longspine snipefish feeds on a variety of crustacean zooplankton such as copepods and ostracods, as well as benthic invertebrates. Seasonal and ontogenetic variations also influence their feeding behavior, with longspine snipefish consuming more amphipods and gastropods during winter. Research has shown that snipefish have a unique elastic recoil-powered feeding mechanism similar to that of seahorses and pipefish. This mechanism enables them to rotate their heads rapidly to capture prey in as little as 2 milliseconds. Macroramphosus scolopax also serves as prey for the Roseate Tern. It has a δ¹³C value of -20.85‰, which makes it a low-energy prey for Roseate Tern chicks, potentially hindering optimal chick growth. Relying solely on Macroramphosus scolopax as a food source could threaten chick survival and fledging success. ==Distribution==

This fish is found worldwide in tropical to subtropical waters in the Atlantic, Indian, and west Pacific Oceans. It has also been observed in the eastern Pacific off Santa Catalina Island, California. The snipefish occurs mainly in temperate latitudes at 20–40°N, although it also occurs in the southern hemisphere down to 43°S. They are typically found at depths of 25 to 600 m (82 to 1,969 ft), especially favoring depths exceeding 100 meters, with a clear preference for deeper areas along the continental shelf and slope regions. ==Reproduction==

Male fish change color before courtship to attract females. The brownish ventral area and the base of the dorsal spine become darker, while the posterior part of the body turns brick red. This dark area extends forward along the back and the sides. This color pattern can disappear within seconds if the fish are startled. Male fish exhibit aggressive behavior during the courtship period, and these fights are closely related to gaining mating opportunities. Typically, longspine snipefish maintain a head-down posture, but two competing males will swim parallel toward each other instead of maintaining the head-down position. Parallel swimming serves as a signaling behavior, with actual competition occurring afterward. Hitting another male with an erect dorsal spine is a common aggressive behavior between males during courtship. In this behavior, one male rapidly swims toward its opponent, turning its back toward the other fish and striking with the raised dorsal spine. The attacking fish then swims away to gain distance, allowing for better aim and speed in the charge. The attacked fish typically remains stationary in a head-down position and may roll its body to minimize exposure. Courtship occurs in the late afternoon, beginning with the fish near the bottom. Courting males follow and swim parallel to the female near the bottom in a head-down position. When a male fish gets close enough, the female erects her dorsal spine. The male follows the female's movement, frequently changing position from one side to the other. Then, the male slowly bends his caudal peduncle toward the female at a 90-degree angle, while the female moves her abdomen toward the male. The two fish join by their caudal peduncle and become united. Together, they ascend to the surface, where the genital papilla of the female extends and contacts the male's genital region repeatedly during the ascent. Eggs are produced and fertilized during this ascent process. The fish separate upon reaching the water surface and return to the bottom. The author of the referenced study suggested that the ascent duration and termination at the surface may be influenced by experimental conditions, such as the limited depth of the tank used in observation. ==Conservation status==

The longspine snipefish (Macroramphosus scolopax) is listed as "Least Concern" on the IUCN Red List. ==References==