J. Wesley Neal

In temperate reservoirs, habitat quality and availability can be vital to year-class formation of young largemouth bass. We assessed littoral habitat availability for largemouth bass in a tropical reservoir. Habitat characteristics (slope, substratum, and cover) were measured at 5 water levels (169, 170, 171, 172, and 173 m above mean sea level) at 15 30-m sites in Lucchetti Reservoir. Total structural habitat availability declined sharply at lower water levels, and both inundated terrestrial vegetation and woody debris were absent at the lowest water level examined. Coarse substrates (...

We validated otolith daily rings of Cichlasoma managuense using immersion in alizarin complexone to provide a known-age reference mark. Cichlids were stocked at 38 fish/cage into 3 121-liter cages with 5-mm mesh size within an experimental pond in Puerto Rico. The smallest 78% immediately escaped the cages and were at large in the ponds. Initial total length of cage cichlids averaged 26.5 mm compared to 20.4 mm for cichlids at large in the pond, although pond cichlids quickly overcame this deficit and realized growth rates 2 times faster than confined cichlids (1.42 mm/day vs. 0.69 mm/day...

We analyzed the efficacy of alizarin complexone (AC) immersion for creating visible fluorescent marks on otoliths of Mozambique tilapia (Tilapia mossambica) and compared the success of processing the otoliths as whole mounts and sections. We immersed 51 tilapia in a buffered 21 C aerated bath of 100 mg/liter AC for 15 hours, and no mortality resulted from marking procedures. Otoliths were removed on days 1, 10, 20, 30, and 60 following marking. Whole ground mounts showed visible rings only 84% of the time, many of which were faint or incomplete. Sectioning revealed visible rings 98% of the...

The validity of otolith ageing in Puerto Rico was examined using known-age largemouth bass (Micropterus salmoides) in Lucchetti Reservoir. Age-0 largemouth bass were tagged with binary-coded wire microtags and stocked into the reservoir on 6 separate events between April 1992 and May 1996. Fish were collected throughout the study at ages 1-3 and otoliths and microtags were removed from tagged bass. Of 36 age-1 and older tagged bass recovered, 50% had no discernible otolith rings (read as age 0). Observed ages of all otoliths agreed with true ages only 14% of the time, and often differed by...