Reproductive biology of the "Copey" snail Melongena melongena (Linnaeus, 1758) in Cispata Bay on the Caribbean coast of Colombia

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Authors: Sandra Hernandez and Wolfgang B. Stotz
Date: Dec. 2004
From: Journal of Shellfish Research(Vol. 23, Issue 3)
Publisher: National Shellfisheries Association, Inc.
Document Type: Article
Length: 4,242 words

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ABSTRACT The reproductive cycle of the "Copey" snail Melongena melongena at Cispata Bay was examined from October 1998 to September 1999. Gonad maturation was studied through macroscopic and microscopic observations on the gonads of females >70 mm (total shell height), showing that individuals were mature throughout the year, but with a period of maximal maturity in March which coincided with the time of maximum recruitment. The mean size at first maturity was 52 mm for males and 65 mm for females. A small number of intersex individuals (4%) (masculinized females, with a normally developed ovary and a rudimentary penis; feminized males with a normally developed testis and gonopore) occurred at intermediate sizes. The proportion of males in the population decreases with the increase in individual size, with only females present at the biggest sampled size-class (mean size of 98.5 mm shell height), suggesting protandric hermaphroditism. If this is proven to be true, artisanal fishing preferring larger animals, could severely interfere in the success of reproduction.

KEYWORDS: Reproductive cycle, Melongena melongena, Caribbean, protandric hermaphroditism, intersex,.

INTRODUCTION

The "Copey" snail Melongena melongena (Linnaeus, 1758) is widely distributed in the Gulf of Mexico, the Caribbean and the Antilles. The snail lives on the shallow areas of coastal lagoons, mangroves and estuaries, being an important component of the fauna on soft or muddy bottoms. The snail tends to concentrate on areas with high densities of its prey, which are bivalves, other gastropods, ascidians and carrion (Hathaway & Woodburn 1961, Hawkins 1973, Rodriguez 1976, Flores 1980, Cosel 1986, Morton 1986, Dalby 1989, Villareal 1989, Bowling 1994). Considering this behavior, fishers sometimes use mangrove roots, covered with the mitilid Mytilopsis soller as bait, letting the snails aggregate on the bait from one day to the next. The method of collection of these snails includes walking over the bottom and locating the snails beneath the mud with the foot. By doing this, the fishers are not able to discriminate size, all sizes being fished. M. melongena attains sizes up to 200 mm of shell height (Clench & Turner 1956, Abbott 1974, Flores 1980, Diaz & Puyana, 1994). In Cispata Bay individuals between 12 and 151 mm shell height are found, the mean size of capture being 57 mm.

M. melongena copulates from December to July in Colombia (Rodriguez 1976) and then produces egg capsules. Egg masses of M. melongena have a common basal layer. The number of capsules produced fluctuates between 27-31, located along a string which measures up to 218 mm in length. Some modified, sterile egg capsules are produced and serve to anchor the egg mass on the soft bottom. This sterile capsules are smaller than fertile capsules, but have the same shape and are spaced approximately 28 mm apart at one end of the string. The average distance between fertile capsules along the string is only 6 mm, this distance getting shorter towards the last capsules produced. Egg masses are mostly buried in soft bottoms close to the vegetation on the coast. The capsules...

Source Citation

Source Citation
Hernandez, Sandra, and Wolfgang B. Stotz. "Reproductive biology of the 'Copey' snail Melongena melongena (Linnaeus, 1758) in Cispata Bay on the Caribbean coast of Colombia." Journal of Shellfish Research, vol. 23, no. 3, Dec. 2004, pp. 849+. Accessed 26 Nov. 2022.
  

Gale Document Number: GALE|A130777671