ISSN:
1095-8649
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Biologie
Notizen:
Submersible data from two areas along the Carolina-Virginia continental slope reveal a Hatteras upper middle slope (HMS) (35.30’N, 74.50’W) demersal fish fauna remarkable for diminutive size of individuals within and across species, a fauna which is accordingly termed ‘Lilliputian’. Contrast of HMS submersible data with Virginia trawl and submersible data support this finding. The four top-ranking HMS fishes, Lycenchelys verrillii, Glyptocephalus cynoglossus, Myxine glutinosa and Nezumia bairdii, are all significantly smaller than on the Virginia upper middle slope. Also peculiar to the HMS is the dominance of sedentary benthic species, rarity of active benthopelagic foragers, and markedly elevated fish population density. Species composition of the HMS fauna differs from that of the general Middle Atlantic Bight fauna; notably absent are species of otherwise continuous distribution along the U.S. East Coast (e.g. Synaphobranchus affinis, Nezumia aequalis). Since HMS megafaunal and macrofaunal invertebrate communities are also anomalous, the Lilliputian phenomenon among HMS bottom fishes provides a characteristic biotic signature of a pervasively re-structured benthic boundary layer community. The authors hypothesize that the HMS faunal anomaly reflects a limiting factor, episodic sediment surface hypoxia, peculiar to this region of high particulate organic carbon flux from surface waters. Results indicate that substantial changes in fish faunal composition and structure can occur on a small geographic scale on the open soft-Substrate continental slope.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1095-8649.1996.tb06069.x
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