POPULATION ECOLOGY OF PAGURUS MACLAUGHLINAE GARCIA-GOMEZ (DECAPODA: ANOMURA: PAGURIDAE) IN THE INDIAN RIVER LAGOON, FLORIDA

• Published in: Journal of crustacean biology 1994-01, Vol.14 (4), p.686-699
• Main Authors: Tunberg, Björn G., Nelson, Walter G., Smith, Graeme
• Format: Article
• Language: English
• Subjects: Crabs; Crustaceans; Experimentation; Female animals; Hermit crabs; Marine; Marine ecology; Pagurus maclaughlinae; Population ecology; Predation; Predators; Sea grasses
• ISSN: 0278-0372; 1937-240X
• DOI: 10.1163/193724094X00650

ABSTRACT Pagurus maclaughlinae is an abundant component of sea-grass macrobenthos in Florida waters. As a grazer on sea-grass blades, it may play an important role in sea-grass ecology by reducing epiphyte cover on the blades. Population dynamics, habitat selection and utilization patterns, and interactions with a decapod predator were examined in field collections and laboratory experiments. At a site north of Link Port in the Indian River Lagoon, Florida, P. maclaughlinae was more abundant in beds of Thalassia as compared to those of Syringodium or Halodule. In the laboratory, Syringodium was selected in preference to Thalassia and Halodule, and choice was not influenced by presence of a predator. Sea grass with epiphytes was significantly selected over unfouled substrates. Recruitment occurred in October-February and in May-July, and the overall male/female ratio was close to 1, although month to month variation occurred. High percentages of ovigerous females were found in the fall and in the spring, and female maturation occurred at a CL of approximately 1.25-1.50 mm. Cerithium muscarum, Modulus modulus, and Nassarius vibex constituted -94% of the 13 species of gastropod shells used. Shell utilization differed between sexes, ovigerous and nonovigerous females, and among size classes. Predation experiments with the blue crab Callinectes sapidus suggested that predation rate was independent of shell species, that the presence of Thalassia offered significant protection against predation compared with bare sand, and that predation rates were not different between sea grasses.