NOTE Graham and Castellanos: Courtship and spawning behaviors of carangid species in Belize 



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Materials and methods 



Turneffe Elbow (17°09'N, 87°54'W) and Gladden Spit 

 (16°35'N, 88°00'W) are two sites located on the Belize 

 Barrier Reef that were monitored for abundance and 

 behavior of many species of spawning reef fish between 

 1999 and 2002. Both sites are promontories with a slop- 

 ing reef shelf that drops off steeply at a depth of 35-45 

 m to over 1000 m into the southern tip of the Cayman 

 Trench. According to the spawning aggregation criteria 

 developed by Domeier and Colin (1997), Turneffe Elbow 

 and Gladden Spit attract, respectively, an estimated 13 

 and 27 species of reef fish that aggregate seasonally to 

 spawn (Graham, 2003). 



We logged over 270 hours of underwater monitoring 

 of reef fish spawning aggregations at Turneffe Elbow 

 and Gladden Spit, primarily from the full-moon to the 

 new-moon from March to July from 2000 through 2002. 

 Additional dives took place variously over the course of 

 3-5 days during the same lunar period from 1999 to 

 2002. Most dives for monitoring spawning aggregations 

 took place between 0830 and 1100 hours, at midday, 

 and between 1600 to 1730 hours of each diving day. 

 Dives began 150-250 m north of both spawning aggre- 

 gation sites and proceeded to the south along the reef 

 platform edge. Dive depth usually began at about 30 m 

 and decreased to 15 m as the dive progressed because 

 of SCUBA decompression constraints. Dives normally 

 lasted between 35 and 50 minutes. Horizontal and ver- 

 tical visibility rarely dropped below 20-25 m. 



Results and discussion 



During 10 dive surveys (15 diving hours) at Turneffe 

 Elbow, we observed a large school of 250 to 500 permit 

 aggregating on the reef promontory (Table 1). The 

 aggregated fish slowly swam into the south current 

 along the south-facing sloping fore-reef shelf at 5-15 m 

 depth and the steep drop-off located at -30-35 m. 

 The school streamed down to the spur and groove for- 

 mations at about 20 m depth on the reef shelf and rose 

 up into the upper water column again. Permit were 

 loosely grouped and displayed little fear of divers, a 

 behavior commonly observed among a range of other 

 fish species that aggregate to spawn (Graham, 2003). 

 Several individuals displayed a dark patch located above 

 and behind the pectoral fin on both flanks. Permit dis- 

 played this same behavior coloration change during 

 each encounter. 



On 22 August 2000, 7 days after the full moon, at 

 -1730 (41 minutes before sunset at 1811 hours local 

 time) we conducted our standard north to south fish 

 census dive at a depth of -20-30 m along the fore-reef 

 drop off. During all dives horizontal and vertical visibil- 

 ity was at least 20 m and often over 40 m. We observed 

 a school of -300 permit descend from 5-15 m depth 

 above the fore-reef drop-off to 25 m directly on the shelf 

 edge. At -1745 hours (26 min before sunset) within- 

 group activity increased as permit schooled densely on 



the edge of the reef drop-off. At -1750 hours, a subgroup 

 of eight permit left the dense school and ascended in 

 the water column to -18 m depth. The lead individual 

 initiating the ascent was -100 cm FL and was pursued 

 by seven fish ranging from -55 to 75 cm FL. The pursu- 

 ing fish nuzzled the larger fish's vent as it rose in the 

 water column. All fish displayed a dark flank patch 

 behind their pectoral fins. The lead permit then ceased 

 its ascent at -15 m, tilted its head down slightly and 

 convulsed rapidly, releasing a puff of gametes. Pursu- 

 ing permit tried to position their vents as closely as 

 possible to the lead individual's while releasing their 

 gametes. The resulting gamete cloud was less than 50 

 cm in diameter and dispersed within seconds (Fig. 1). 

 Following gamete release, all fish descended quickly to 

 the main school still located -25 m below. Within mo- 

 ments this behavior was repeated and observed in two 

 smaller groups of permit before all observations ceased 

 because of a lack of light. 



At Gladden Spit, we observed slightly different permit 

 spawning behavior. On 7 April 2002 (10 days after the 

 full moon), the aggregation remained in a restricted 

 area -100 m north of where we previously witnessed 

 the spawning of several species of fish and -30 m east 

 of where we have also observed groupers Epinephelus 

 striatus, Mycteroperca tigris, M. venenosa, and M. bonaci 

 aggregate to spawn (Graham, 2003). Ambient water 

 temperature was 27.7°C as measured by a temperature 

 logger (Onset Corp. Tidbit data logger) moored at the 

 spawning site at 30 m depth. 



At least 300 permit — many of them large individuals 

 (-70-90 cm FL)— schooled densely into a ball at -1700 

 hours (66 minutes before sunset local time) near the 

 reef shelf drop-off at a depth of -40-48 m. Subgroups 

 comprised five to nine fish, and the lead fish was much 

 larger than the pursuers. Subgroups rapidly rose up on 

 the periphery of the school, spawned at the apex of the 

 aggregation, and descended towards the bottom of the 

 school again. Spawning was more frenetic than that 

 observed at Turneffe Elbow. Permit subgroups behaved 

 in the same manner as that observed at Turneffe dur- 

 ing spawning, and all spawning individuals displayed a 

 large dark flank patch behind the pectoral fins. 



Based on our observations of courtship and spawn- 

 ing behavior, our estimate of spawning season for per- 

 mit in Belize may stretch from February to the end of 

 October, beyond the period of March to September as 

 suggested by Garcia-Cagide et al. (2001) and Crabtree 

 et al. (2002). Permit may also reach larger sizes than 

 published by Crabtree et al. (2002); we estimated the 

 largest individual permit observed at Turneffe Elbow 

 in Belize to be -120 cm FL, which may indicate that 

 permit exceed a lifespan of 23 years. 



We could not determine if the lead permit was fe- 

 male and the pursuing permit were males because no 

 individuals were caught for gonadal analysis. However, 

 carangids are gonochoristic and it is highly likely that 

 the lead fish in the spawning rush was female. Garcia- 

 Cagide et al. (2001) noted that spawning females are 

 often larger than mature males in several species of 



