Vertical distribution and substratum association of Halacaridae (Acari: Prostigmata) on sheltered and exposed Irish shores

Abstract

Abstract Halacaridae, particularly Rhombognathinae, are often associated with the dominant macroalgae, especially Fucaceae, on sheltered shores of the boreal Atlantic Ocean. Although the communities of algae and barnacles available to Halacaridae as substrata differ between wave-exposed and sheltered shores, the halacarid communities present, and their distribution, are essentially similar. Comparison of substratum associations of Halacaridae on exposed shores with those on sheltered shores suggests that microenvironmental factors are important in determining halacarid distributions. Site retention by adult Halacaridae plays a major role in maintaining these distributions. Keywords : AcariHalacaridaeLittoralsubstratawave exposurephytal meiofaunaIreland