Six sciaenid species including Johnius tingi, Johnius sina, Pennahia argentata, Pennahia pawak, Chrysochir aureus and Otolithes rubber from the western coast of Taiwan were studied. Pennahia argentata¡¦s disturbance sound was most distinct in which the pulse period is almost 2~3 times larger than that the other five sciaenid species. The dominant frequencies of C. aureus and O. rubber¡¦s disturbance calls were low (i.e. usually below 500 Hz). In the six sciaenids there was significant difference in the pulse repetition rate, which may be a useful parameter for recognition of sciaenid species. Among the other fishes surveyed in this study, the inter-pulse interval of pearlperch¡¦s (Glaucosoma buergeri) disturbance call is very short or nearly zero. The pulse is composed a low frequency and a high frequency parts, and the frequency range is wide. Most energy was concentrated in the 2nd and 3rd pulses of the Priacanthus macracanthus¡¦s disturbance soundand its pulse period is not stable. The special acoustic character of Pelates quadrilineatus¡¦s disturbance sound is the extremely short inter-pulse interval (< 1ms).The seacatfish Arius maculates¡¦s disturbance sound can be sorted into three types. Type¢¹is a low frequency sound and usually under 1000Hz; it is very similar to sciaenids¡¦ calls with stable pulse period and dominant frequency. Compared to Type¢¹, Type¢º and Type¢» were high-frequency sounds (i.e. usually up to 8kHz) and their pulse periods are less stable. Pomadasys kaakan¡¦s disturbance sound is emitted by stridulating of its pharyngeal teeth and these sounds were high frequency (i.e. usually higher than 10 kHz). Both Johnius tingi females and males possess extrinsic sonic muscles. The dominant frequency of the males¡¦ disturbance call is significant higher than that of females¡¦ and the length of males¡¦ sonic muscles are also significantly longer than that of females¡¦. It is hypothesized that a longer sonic muscle can generate higher tension leading to a higher frequency sound. Comparing my data to the eleven sound types collected from the western coast by other workers in which the sound producers are still unknown, Type A, Type F, and Type G are more similar to that of the disturbance sound of J. sina¡BP. pawak and J. belengerii, respectively.

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-08-02T20:49:26Z No. of bitstreams: 2 Dissertacao_AlimentacaoDistribuicaoEspacial.pdf: 6094614 bytes, checksum: a11694c7bda2f52c1499467bd3a32633 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-08-16T15:26:50Z (GMT) No. of bitstreams: 2 Dissertacao_AlimentacaoDistribuicaoEspacial.pdf: 6094614 bytes, checksum: a11694c7bda2f52c1499467bd3a32633 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2013-08-16T15:26:50Z (GMT). No. of bitstreams: 2 Dissertacao_AlimentacaoDistribuicaoEspacial.pdf: 6094614 bytes, checksum: a11694c7bda2f52c1499467bd3a32633 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 1999 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Pertencente a ordem dos Siluriformes, a família Ariidae compreende os bagres marinhos e estuarinos os quais distribuem-se pelas costas de todos os continentes, habitando áreas costeiras de região tropical e subtropical, onde vivem em águas de pouca profundidade, com fundo arenoso ou lodoso. No estuário Amazônico, no estado do Pará, encontram-se 7 espécies pertencentes ao gênero Anus (A. couma, A. parkeri, A. rugispinis, A. quadriscutis, A. grandicassis, A. phrygiatus e A. proops). O objetivo deste estudo é identificar os hábitos alimentares, sobreposição alimentar e espacial, distribuição espacial e sazonal das espécies de Anus (Siluriformes, Ariidae) do Estuário Amazônico. As coletas foram realizadas durante o período de agosto a outubro de 1996, de fevereiro a abril e agosto a outubro de 1997. Os indivíduos foram capturados com rede de fundo sem porta da frota piramutabeira do estuário Amazônico. Existem dois grupos de espécies do gênero Anus: as espécies que se alimentam de crustáceos (A. rugispinis, A. quadriscutis, A. grandicassis, A. phrygiatus e A. proops) e as espécies que se alimentam de peixes (A. couma, A. parken). Com relação a sobreposição alimentar todas as espécies apresentam um certo grau sobreposição alimentar assim como a sobreposição espacial. A. couma e A. phrygiatus estão mais abundantes nos estratos de profundidade entre 5-10 m e A. rugispinis, A quadriscutis, A. grandicassis, A. parkeri e A. proops nos estrato de 10-20 m. A. phrygiatus é a única espécie que apresenta maior abundância durante o inverno e as demais espécies aparecem tanto no verão como no inverno / The Family Ariidae (Order Siluriformes) contains marine and estuarine catfishes distributed along the coasts of ali the continents, inhabiting tropical and subtropical shores where they live in shallow waters with sandy or muddy bottoms. In the Amazon River estuary in Pará State, Brazil, there are seven species belonging to the genus Anus (A. couma, A. parkeri, A. rugispinis, A. quadriscutis, A. grandicassis, A. phrygiatus e A. proops). The aim of this study is to identify feeding preference, feeding overlap, spatial distribution and seasonal distribution of the species of genus Anus (Siluriformes, Ariidae) of the Annazon stuary. Collections were made from August to October 1996, and February to April and August to October 1997. Specimens were captured with bottom nets without escape doors belonging to the piramutaba fishing fleet of the Amazon estuary. There are two species groups in the genus Anus: those that feed on crustaceans (A. rugispinis, A. quadriscutis, A. grandicassis, A. phtygiatus e A. proops), and those that feed on fish (A. couma, A. parken). In relation to feeding overlap, ali the species demonstrated a certain degree of feeding overlap, as well as spatial overlap. A. couma and A. phrygiatus. are the most abundant in the 5-10 m depth range and A. rugispinis, A. quadriscutis, A grandicassis and A. parkeri e A. proops in the 10-20 m range. A. phrygiatus is the only species that has a greater abundance during the rainy season, and the other species are present both in the dry as well as the rainy season.