Abundance, distribution, and secondary production of the apple snail Pomacea flagellata (Say, 1829) in Bacalar Lake, a tropical karstic system in southern Mexico

ABSTRACT

Pomacea flagellata is a gastropod conspicuous in freshwater environments, and represents a fishing resource. To assess their abundance, distribution, and secondary production, monthly samplings were carried out in Bacalar Lake from June 2012 to May 2013 at 12 sampling sites. In each site, three random transects were marked parallel to the shore. All snails on transect were collected and shell length and wet weight measured. The highest density occurred in September (1.27 ind.m⁻²), lowest in October (0.47 ind.m⁻²). Shell lengths ranged from 2 to 56 mm, with recruitment in January–March. Growth parameters were L_∞ 59.50 mm, K 0.65.year⁻¹; the lifetime span was 3 years. Average biomass reached 5.57 wet g.m⁻² and secondary production was 6.025 wet g.m⁻².year^-1; annual renewal rate P/B 1.08. Highest abundance and secondary production was contributed by individuals between 31 and 41 mm in length. A potential biomass of 25.06 tons of snails was estimated in the lake. Snail densities, secondary production, and turnover were very low during the year, indicating that it is not viable to consider a commercial catch without affecting the population. A ban of 10 years is proposed, and aquaculture practices of snails are recommended to recover the resource.

KEYWORDS:

• Freshwater
• mollusk
• gastropod
• population

Geolocation Infomation

Study Area 1 (point): 18 32´41.66“N, 88 27´3.96”W; Study Area 2 (point): 18 56´7.95“N, 88 9´12.30”W; Study Area 3 (point): 18 56´46.3“N, 88 9'36.40”W; Study Area 4 (point): 18 33´4.61“, N 88 27´59.29”W

Acknowledgments

We appreciate very much the help of Raul Mézquita Marinero and Williams Reyes Gamboa in collecting field data. Pablo Ramirez-Barajas reviewed the statistical methods and Birgit Schmook reviewed the manuscript. We are grateful for the contributions of two anonymous reviewers.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was granted by Fondo Mixto CONACYT-Quintana Roo, Project: QROO-2011-C01-175156. A.J.N. was responsible for the project.