Distribution and relative abundance of flyingfish (Exocoetidae) in the eastern Caribbean. II. Spawning substrata, eggs and larvae

Abstract

We investigated the distribution and relative abundance of flyingfish spawning substrata (flotsam), eggs and larvae by neuston tows at 40 stations across a 67 500 square nautical mile (mm2) area of the eastern Caribbean from April 10 to May 6, 1988. Flotsam occurred m only 48% of the tows and in quantities < 1 g n m i l tow. Non-buoyant flyingfish eggs characteristic of Huundichthys affmis, Parexocoetus brachypterus and Cypselurus cyanopterus were virtually absent. Although 21 % of the 3014 fish eggs collected were flyingfish eggs, all but 3 of these were pelagic eggs characteristic of Exocoetus spp. The rarity of eggs and flotsam suggests that flyingfish may typically spawn on floating material until it submerges, and/or spawn on submerged substrata. Catch rates of all fish larvae and of flyingfish larvae were significantly higher in day tows than night tows, and mean larval size was larger by night. This indicates that larvae, and particularly smaller larvae, may move downwards at night. This may be a light response, since P. brachypterus larvae were more abundant at the surface around full moon than new moon. Larval abundance varied significantly across the survey area for all flyingfish, and separately for E. voLitans, P. brachypterus and C. cyanopterus. Small larvae of E. volitans were more abundant at oceanic than coastal stations. The reverse was true for P. brachypterus, indicating different spawning locations for these species. The geographical distribution of larvae of C. cyanopterus coincided with the adult distribution, both larvae and adults being rare in the southwest sector of the survey area near the South American mainland. Larvae of H. affims were relatively rare. This rarity, and the virtual absence of eggs, is surprising given the abundance of this species in the eastern Caribbean and the fact that H. affms was known to be spawning during the time of the survey. The depth at which H. affms typically spawns and hatches requires further investigation.

Small-scale spatial and temporal variability of larval fish assemblages at an isolated oceanic island

“…Flyingfishes, for example, congregate around islands during their breeding season when adults spawn near rocky substrates (Hunte et al 1995). At Saint Paul's Rocks, flyingfishes such as Cypselurus cyanopterus spawn in the first quarter of the year when yellowfin tuna Thunnus albacares catches are high (Lessa et al 1999, Hazin et al 2009).…”

Biology of the dolphinfish (<i>Coryphaena hippurus</i>) in the western central Atlantic: a review

“…Larval dolphinfish have been reported off Barbados year-round (Lao, 1989), and both larval and juvenile dolphinfish have been sampled in the southeastern Caribbean waters during April/May Hunte et al, 1995).…”

Distribution and relative abundance of flyingfish (Exocoetidae) in the eastern Caribbean. III. Juveniles

“…6). Interestingly, variation in the abundance of E. volitans juveniles (mean length 52.2 mm FL) between stations was highly correlated with variation in abundance of E. volitans larvae taken in neuston tows (mean length 32.14 mm FL, Hunte et al 1995; Spearman rank correlation: rs = 0.836, n = 20, p < 0.001).…”

“…4). Interestingly, the variation between stations in abundance of P. brachypterus larvae as determined by neuston tows (mean length 34.5 rnm FL; Hunte et al 1995) was significantly correlated with the variation in abundance of the smaller size group of juveniles taken by the dipnet (mean length 42.9 mm FL; Spearman rank correlation: rs = 0.699, n = 20, p < 0.002), but not with the larger size group of the juveniles taken by the dipnet (mean length 84.0 mm FL; Spearman rank correlation: r, = 0.029, n = 20, p = 0.899). The adults of P. brachypterus were most abundant east of Barbados and Tobago, an area in which visual surveys also detected high abundance .…”

“…The distribution and relative abundance of flyingfish spawning substrata, eggs, larvae and adults in the eastern Caribbean have been investigated by Oxenford et al (1995, this issue; for adults) and Hunte et al (1995, this issue; for other life history stages). The visual survey technique used for adults and the neuston tows used for eggs and larvae provide no information on the considerable size range of flyingfish juveniles too large to be captured by neuston tows and too small to be detected by visual surveys.…”