Population Dynamics and Description of Ptycholaimellus hibernus n. sp. (Nematoda: Chromadoridae).

Ptycholaimellus hibernus n. sp. from the muddy subtidal of North Inlet Estuary, Georgetown, South Carolina, is described and a key to the genus is provided. P. hibernus differs from all other species of Ptycholaimellus by the shape of the gubernaculum. Ptycholaimellus sp. 2 Hopper 1969 is synonymized with P. ponticus. The abundance of P. hibernus, measured over a 3-year period, is greatest from January to March, coinciding with minimal annual water temperatures (10-15 C). P. hibernus abundance was significantly (negatively) correlated with water temperature and (positively) with the depth of the anoxic sediment layer.