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生物学
Differences in pectoral fin spine morphology between vocal and silent clades of catfishes (Order Siluriformes): Ecomorphological implications
<正> Stridulatory sound-producing behavior is widespread across catfish families, but some are silent. To understand why,we compared spine morphology and eeotype of silent and vocal clades. We determined vocal ability of laboratory specimens duringdisturbance behavior. Vocal families had bony (not flexible or segmented) spines, well-developed anterior and/or posteriorserrations, and statistically significantly longer spines. We compared morphology of the proximal end of the pectoral spine betweenvocal and silent species. For vocal taxa, microscopic rounded or bladed ridges or knobs were present on the dorsal process.Most silent species had reduced processes with exclusively smooth, convoluted, or honeycombed surfaces very similar tospine-locking surfaces, or they had novel surfaces (beaded, vacuolated, cobwebbed). Most callichthyids had ridges but many weresilent during disturbance. All doradid, most auchenipterid and most mochokid species were vocal and had ridges or knobs.Within the Auchenipteridae, vocal species had spines with greater weight and serration development but not length. Silentauchenipterids had thin, brittle, distally segmented spines with few microscopic serrations on only one margin and a highly reduceddorsal process lacking any known vocal morphology. Silent auchenipterids are derived and pelagic, while all vocal generaare basal and benthopelagic. This is the first phylogenetic evidence for stridulation mechanism loss within catfishes. Phylogeneticmapping of vocal ability, spine condition, and eeotype revealed the repeated presence of silence and vocal taxa, short and longspines, and eeotype shifts within clades. The appearance and loss of vocal behavior and supporting morphologies may have facilitateddiversification among catfishes
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Current Zoology
2010年01期

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