Settlement of the barnacle Balanus trigonus Darwin, 1854, on Panulirus gracilis Streets, 1871, in western Mexico

Abstract A large number of specimens (2765) of the acorn barnacle Balanus trigonus Darwin, 1854, were observed on the spiny lobster Panulirus gracilis Streets, 1871, in western Mexico, including recently settled cypris (1019 individuals or 37%) and encrusted specimens (1746) of different sizes: <1.99 mm, 88%; 1.99 to 2.82 mm, 8%; >2.82 mm, 4%). Cypris settled predominantly on the carapace (67%), mostly on the gastric area (40%), on the left or right orbital areas (35%), on the head appendages, and on the pereiopods 103. Encrusting individuals were mostly small (84%); medium0sized specimens acc...