Stridulatory sound-producing behavior is widespread across catfish families, but some are silent. To understand why, we compared spine morphology and ecotype of silent and vocal clades. We determined vocal ability of ...Stridulatory sound-producing behavior is widespread across catfish families, but some are silent. To understand why, we compared spine morphology and ecotype of silent and vocal clades. We determined vocal ability of laboratory specimens during disturbance behavior. Vocal families had bony （not flexible or segmented） spines, well-developed anterior and/or posterior serrations, and statistically significantly longer spines. We compared morphology of the proximal end of the pectoral spine between vocal 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 to spine-locking surfaces, or they had novel surfaces （beaded, vacuolated, cobwebbed）. Most callichthyids had ridges but many were silent 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. Silent auchenipterids had thin, brittle, distally segmented spines with few microscopic serrations on only one margin and a highly reduced dorsal process lacking any known vocal morphology. Silent auchenipterids are derived and pelagic, while all vocal genera are basal and benthopelagic. This is the first phylogenetic evidence for stridulation mechanism loss within catfishes. Phylogenetic mapping of vocal ability, spine condition, and ecotype revealed the repeated presence of silence and vocal taxa, short and long spines, and ecotype shifts within clades. The appearance and loss of vocal behavior and supporting morphologies may have facilitated diversification among catfishes [Current Zoology 56 （1）： 73 89 2010].展开更多
This article investigates the formative influence of voice on the argumentative writing performance of intermediate students of English. Its aim is to achieve a better understanding of how the students＇ voice develop...This article investigates the formative influence of voice on the argumentative writing performance of intermediate students of English. Its aim is to achieve a better understanding of how the students＇ voice develops in the revision process in relation to the rubric and the essay scores. The data consist of Chinese sophomores＇ multi-draft essays. As first-person pronouns are the most visible representation of a writer＇s voice, this article gives a detailed description of the features and developmental patterns of first-person pronouns （FPPs）. The results reveal that revision-induced changes in FPP can be beneficial to the quality of essay writing but only in a limited number of cases if the students are not formally instructed in voice, which carries pedagogical implications to empower students＇ self-identity in EFL writing.展开更多
基金the Barbara-Sussman FundSigma-Xi+1 种基金SUNY-ESFsupported by MIMH training grant 5-T32-MH15793
文摘Stridulatory sound-producing behavior is widespread across catfish families, but some are silent. To understand why, we compared spine morphology and ecotype of silent and vocal clades. We determined vocal ability of laboratory specimens during disturbance behavior. Vocal families had bony （not flexible or segmented） spines, well-developed anterior and/or posterior serrations, and statistically significantly longer spines. We compared morphology of the proximal end of the pectoral spine between vocal 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 to spine-locking surfaces, or they had novel surfaces （beaded, vacuolated, cobwebbed）. Most callichthyids had ridges but many were silent 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. Silent auchenipterids had thin, brittle, distally segmented spines with few microscopic serrations on only one margin and a highly reduced dorsal process lacking any known vocal morphology. Silent auchenipterids are derived and pelagic, while all vocal genera are basal and benthopelagic. This is the first phylogenetic evidence for stridulation mechanism loss within catfishes. Phylogenetic mapping of vocal ability, spine condition, and ecotype revealed the repeated presence of silence and vocal taxa, short and long spines, and ecotype shifts within clades. The appearance and loss of vocal behavior and supporting morphologies may have facilitated diversification among catfishes [Current Zoology 56 （1）： 73 89 2010].
文摘This article investigates the formative influence of voice on the argumentative writing performance of intermediate students of English. Its aim is to achieve a better understanding of how the students＇ voice develops in the revision process in relation to the rubric and the essay scores. The data consist of Chinese sophomores＇ multi-draft essays. As first-person pronouns are the most visible representation of a writer＇s voice, this article gives a detailed description of the features and developmental patterns of first-person pronouns （FPPs）. The results reveal that revision-induced changes in FPP can be beneficial to the quality of essay writing but only in a limited number of cases if the students are not formally instructed in voice, which carries pedagogical implications to empower students＇ self-identity in EFL writing.
