Catfish pectoral spines are an anti-predator defense mechanism. They can be bound or locked, making the fish harder to swallow, or used to produce distress calls by rubbing ridges on the dorsal process against a channel in the wall of the pectoral girdle. Growth of the pectoral spine and girdle were examined in relation to fish size within and across species that occur throughout central and eastern Virginia. These included blue catfish (Ictalurus furcatus), channel catfish (Ictalurus punctatus), white catfish (Ameiurus catus), brown bullheads (Ameiurus nebulosus), yellow bullheads (Ameiurus natalis), flathead catfish (Pylodictis olivaris), margined madtom (Noturus insignis), and tadpole madtom (Noturus gyrinus).Pectoral spines and girdles grow as catfish increase in size. In larger species spine length and weight increase nonlinearly with fish size, suggesting that maintaining spine dimensions becomes less important in bigger individuals less likely to suffer predation. The incidence of spine breakage also increases in larger fish. In smaller species spine length increases linearly in our samples (brown and yellow bullheads and margined and tadpole madtoms). In all species spine width increases linearly with total length. The spine base (dorsal process width and depth and dorsal-ventral length) grows linearly with total length in most species. However, measurements of the spine base increase nonlinearly in white catfishes, and dorsal process width increases nonlinearly in wild channel catfish although the increase was linear in cultured channel catfish.Girdle depth increased linearly with total length in all species except for wild channel catfish, and the ratio of coracoid to cleithrum depth varied among species. Pectoral girdle weight increased linearly with fish weight in blue catfish, cultured channel catfish, brown bullheads, and margined and tadpole madtoms. However, girdle weight, a major component of the body, increased nonlinearly in wild channel, white, yellow bullheads, and flathead catfishes. Cultured channel catfish had smaller pectoral spines and girdles than wild channels, a likely epigenetic response to predators. Catfish spines were identified to species, allowing determination of catfishes eaten by bald eagles (Haliaeetus leucocephalus) using spines collected near their nests. Bald eagles ate blue catfish (60%), channel catfish (27%), white catfish (9%), brown bullheads (4%) and yellow bullheads (0.5%). Madtom and flathead catfish were not consumed. Mean sizes captured were: Blue catfish (366 mm, 414 g), channel catfish (417 mm, 618 g), white catfish (320 mm, 591 g), brown bullheads (278 mm, 277 g) and yellow bullhead (203 mm, 192 g).

Submitted by (edna.saturno@ufrpe.br) on 2017-02-17T14:47:32Z No. of bitstreams: 1 Railma Maria Vilanova Rocha Queiroz.pdf: 1804552 bytes, checksum: 810d765910ae3d9737fe6905ecc4a3b8 (MD5) / Made available in DSpace on 2017-02-17T14:47:32Z (GMT). No. of bitstreams: 1 Railma Maria Vilanova Rocha Queiroz.pdf: 1804552 bytes, checksum: 810d765910ae3d9737fe6905ecc4a3b8 (MD5) Previous issue date: 2012-07-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The aim of this work was to study age, growth and reproduction of the margined flyingfish Cheilopogon cyanopterus in the area of the Saint Peter and Saint Paul Archipelago (SPSPA, Brazil), where this species has a relevant ecological role, acting as an important link in the epipelagic food chain. During the years 1995 to 2009, were captured mainly by light attraction 4094 specimens. To estimate age and growth was analyzed lapilli otoliths microstructure of 277 individuals, where the number of microstructures ranged from 14 and 383 to individuals with 4.6 to 36.1 cm FL. The “known-age” method was employed for validation of microstructures deposition periodicity, demonstrating a daily formation starting from hatching (Student’s t-test, df = 1 tsa = 0.7973; tsb = 0.9729; p = 12,7). Pairs of age-length data were fitted to four growth models: von Bertalanffy, Gompertz, Logistics and Richards. Based on Akaike’s information criterion and Akaike weight, the Gompertz model best described C. cyanopterus growth, explaining 91.5% of growth for the species. The following parameters were derived for that model: L∞ = 30.4; k = 0.014 e a = 2.53. The reproductive aspects were described using macro and microscopic analysis of the gonads. The analysis of gonadal indices indicated that the spawning season occurs between October and May, with peak March. The total fecundity and Batch fecundity ranged from 24670 to 77409 and 2618 to 66961, respectively, with average of 2.2 lots eliminated during the reproductive period. The maturation occurs in individuals of 22.05 cm CZ with 90 days of age. Histological analysis of gonads showed that 28% of females were mature/hydrated and 72% spawning. The concomitant presence of different stages of oocyte development in histological sections of the gonads which allowed the development of oocytes classified as synchronous in more than two groups, and as batch spawning. / Este trabalho teve como objetivo estudar a idade, o crescimento e a reprodução do peixe-voador-holandês Cheilopogon cyanopterus na região oceânica do Arquipélago de São Pedro e São Paulo onde essa espécie desempenha relevante papel ecológico, atuando como importante elo da cadeia trófica epipelágica. Durante os anos de 1995 a 2009, foram capturados principalmente por atração luminosa 4094 espécimens. Para estimativas de idade e crescimento foi analisada a microestrutura do otólito lápilo de 277 indivíduos, onde o número de microincrementos variou de 14 a 383 para indivíduos com comprimento zoológico (CZ) compreendido entre 4,6 e 36,1 cm. O método “validação com idade conhecida” foi utilizado para validar a periodicidade de formação dos microincrementos o que revelou deposição diária desde a fase embrionária (t-test, df = 1 tsa = 0,7973; tsb = 0,9729; p = 12,7). Os dados de idade e comprimento foram ajustados a quatro modelos de crescimento, von Bertalanffy, Gompertz, Logístico e Richards. Segundo critério de informação Akaike e peso Akaike, o modelo de Gompertz é o que melhor descreve o crescimento C. cyanopterus, explicando 91,5% do crescimento desta espécie. Obteve-se para esse modelo os parâmetros: L∞ = 30,4 cm CZ; k = 0,014 e a = 2,53. A análise dos índices gonadais indicou que o período de desova ocorre entre outubro e maio, com pico em março. A fecundidade total e por lote variou respectivamente de 24670 a 77409 e 2618 a 66961, com média de 2,2 lotes eliminados durante o período reprodutivo. A maturação gonadal começa a ocorrer em indivíduos de 22,05 cm CZ, com 90 dias de idade. A análise histológica das gônadas mostrou que 28% das fêmeas encontravam-se maduras/hidratadas e as demais desovadas. A presença concomitante de diferentes fases de desenvolvimento ovocitário nos cortes histológico das gônadas permitiu classificar o desenvolvimento dos ovócitos como sincrônico em mais de dois grupos, e a desova como parcelada.