MEPS 267:233-240 (2004)  -  doi:10.3354/meps267233

Quantitative changes in the otolithic organs of the inner ear during the settlement period in European hake Merluccius merluccius

Antoni Lombarte1,*, Arthur N. Popper2

1Institut de Ciències del Mar (CMIMA-CSIC), Passeig Marítim 37-49, 08003 Barcelona, Catalonia, Spain
2Department of Biology & Neuroscience and Cognitive Science Program, University of Maryland, College Park, Maryland 20742, USA

ABSTRACT: Qualitative and quantitative observations were made of the density and growth of the sensory epithelia, hair cell number, and otoliths of the 3 pairs of end organs (saccule, lagena, and utricle) of the inner ear of European hake Merluccius merluccius (35 to 100 mm length) caught in the northwestern Mediterranean Sea. This is the period in the hake¹s life-history during which the transition from pelagic to epibenthic forms (settlement period) occurs. The results demonstrate a quantitative inversion in the percentage of the sensory epithelia area and the number of hair cells between the saccule and utricle over this time period. This period is also coincident with the settlement period that takes place when most individuals are ca. 50 mm, at which time the fish become epibenthic. These quantitative changes in the ear could be related to ecological changes in mobility and feeding.

KEY WORDS: Ecomorphology · Inner ear · Sensory hair cells · Otolith · Merluccis merluccius

Full text in pdf format