Madeira Lantern Fish

Oceanodromous. Migrating within oceans typically between spawning and different feeding areas, as tunas do. Migrations should be cyclical and predictable and cover more than 100 km.

High-oceanic, schooling, found between 650-700 m during the day and between 51-250 m at night with size stratification with depth. Juveniles are nyctoepipelagic at the surface. Feeds on copepods and adult/larval forms of other planktonic crustaceans.

High-oceanic, schooling, found between 650-700 m during the day and between 51-250 m at night with size stratification with depth (Ref. 4479). Depth range from 460-1082 m1 in the eastern Ionian Sea (Ref. 56504). Juveniles are nyctoepipelagic at the surface. Feeds on copepods and adult or larval forms of other planktonic crustaceans (Ref. 4775).

Ceratoscopelus maderensis

This species is found in the North Atlantic Ocean and Mediterranean Sea (Bolin, 1959), where it is distributed in a temperate-semisubtropical pattern (Backus et al., 1977). The species ranges as far north as Iceland (Bolin, 1959), and its southwestern limit is approximated by the Gulf Stream edge (Backus et al., 1970), placing the study area outside of its normal range. This moderately large species is known to grow to a size of about 70 mm in the Northwestern Atlantic slope water (Krueger et al., 1975; Jahn, 1976) and in the Mediterranean (Goodyear et al., 1972); maximum size is 81 mm (Hulley, 1981); maximum size in the Ocean Acre collections is 29 mm. It is a “common” lanternfish in the study area, being represented in the collections by a total of 489 fish, 90 of which are from the paired seasonal cruises. Discrete-depth samples account for 47 specimens, 36 of these from noncrepuscular tows (Table 23).

REPRODUCTIVE CYCLE AND SEASONAL ABUNDANCE.—Ceratoscopelus maderensis is an expatriate, presumably not capable of development or prolonged survival in the Ocean Acre area. About 25 percent of the transformed specimens taken were examined for developmental stage and sex. All were juveniles and only two had recognizable ovaries or testes.

Almost all specimens (475) are from collections taken from July through October. The species is virtually absent during the remainder of the year. These data imply that the species is carried into the area from the spawning grounds to the north and that young individuals die soon after arrival.

The appearance of 171 postlarvae in the study area suggests that spawning occurs nearby. However, it is possible that eggs are carried to the south (perhaps in cold core eddies) after they are spawned and continue to develop until conditions become unfavorable. All but two postlarvae were taken during a single cruise in July 1968. The remaining two were taken in late spring (June). Presumably this reflects a spawning peak in the parent population sometime in late spring and early summer, which is similar to that of C. maderensis in the Mediterranean Sea (Taaning, 1918; Goodyear et al., 1972). Jahn (1976) has shown that the species has a strong preference for slope water and has indicated that it probably does not spawn successfully in the northern Sargasso Sea. The present data support the latter contention. The species was moderately abundant in late summer, absent in winter, and scarce in late spring (Table 39).

VERTICAL DISTRIBUTION.—Day depths of occurrence in late summer were 751–1000 m with a maximum abundance at 751–800 m. In late spring a single specimen was taken at 301–350 m. Depth range at night in late summer was 33–250 m and 651–1000 m with a slight peak at 51–100 m. In late spring a single specimen was caught at 50 m (Table 39).

Small juveniles apparently do not migrate regularly. At night in late summer about half of the catch came from day depths (Table 39). All nonmigrants were less than 20 mm. The smallest migrant was 18 mm. Apparently, C. maderensis does not migrate until a size of approximately 19 mm is attained. Goodyear et al. (1972) showed that a similar situation exists in the Mediterranean Sea. Postlarvae were taken at or near the surface; most were from oblique samples.

NIGHT:DAY CATCH RATIOS.—The smaller catch taken at night than by day in late summer (0.4:1) may be due to the greater range of depths occupied at night. Avoidance probably is not a factor, as the largest fish caught in discrete-depth depth samples is 25 mm. Only two specimens were taken in discrete-depth samples in late spring.

Feeds on copepods and adult/larval forms of other planktonic crustaceans

Slope Water and Gulf Streams regions from 50°N to 30°N.

High-oceanic, schooling, found between 650-700 m during the day and between 51-250 m at night with size stratification with depth.

nektonic

Known from seamounts and knolls