MEPS 263:169-175 (2003)  -  doi:10.3354/meps263169

Ultraviolet-absorbing compounds in the mucus of temperate Pacific tidepool sculpins: variation over local and geographic scales

Jill P. Zamzow*

Zoology Department and Hawaii Institute of Marine Biology, University of Hawaii, PO Box 1346, Kaneohe, Hawaii 96744, USA

ABSTRACT: Temperate tidepool fishes of the family Cottidae (Teleostei) display biogeographic distribution patterns that vary with latitude and elevation within the intertidal zone. Middle and high intertidal pool species show a pattern of Œspecies replacement¹, with southern species being replaced by northern species at discrete locations along the coast. Lower intertidal pools, on the other hand, are dominated by a single species, Oligocottus snyderi, that occurs over an extremely wide latitudinal range. As a consequence of both latitudinal and elevational patterns, these fish experience variable amounts of ultraviolet (UV, 280 to 400 nm) irradiation both between and within species. The mucus of tidepool sculpins was analyzed by absorbance spectrophotometry to compare concentrations of UV-absorbing compounds in the mucus of fish, with regard to geographic location or intertidal microhabitat. Mucus from northerly fishes absorbed significantly less UV than the mucus of southerly fishes. Overall, mucus from high intertidal pool fishes absorbed significantly more UV than mucus from middle or lower intertidal pool fishes, but differences were not detectable within a site. The mucus spectra of all fish surveyed contained a single UV absorption peak with maximum absorbance (λmax) in the short-wavelength UVA (UVA = 320 to 400 nm, λmax range = 323 to 331 nm). Compounds with λmax in the UVB (280 to 320 nm) or longer-wavelength UVA (ca. 360 nm) were not found, although these compounds were present in 38 (UVB) and 59% (longer UVA) of tropical species¹ mucus (138 species surveyed).

KEY WORDS: UV · Mycosporine-like amino acid · MAA · Mucus · Oligocottus · Clinocottus

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