Variação sazonal no recrutamento de Phragmatopoma caudata (Polychaeta, Sabellariidae) na costa sudeste do Brasil: biometria e validação de metodologia para categorização de classes etárias

Abstract

ABSTRACT. Seasonal variation in recruitment of Phragmatopoma caudata (Polychaeta, Sabellariidae) in the southeast coast of Brazil: validation of a methodology for categorizing age classes. This study explores the achievement of gametes maturity and biometric analysis of Phragmatopoma caudata Krøyer in Mörch, 1863 to endorse a methodology and provide a proper technique for studies aiming to assess the population ecology. Analysis via Pearson's test confirmed a significant evidence of positive correlation (r = 0.90, P <0.0001) between body length and length of the opercular crown. Individuals with opercular crown ≤ 0.9 mm can be regarded as juvenile due to the absence of gametes. Therefore, through the endorsed method to separate the size classes aimed to analyze the population density and seasonal pattern of the juvenile class. The reef population of P. caudata in the Xixová-Japuí State Park (PEJX) at the Santos Bay, state of São Paulo, was examined for two years. In the highest rate of juveniles, population density reached 128,115 ind./m 2 , however, the average was 65,090 ind./m 2 . Statistical analyzes (Kruskal-Wallis H = 1.475, p < 0.01) showed that significant temporal variation occurs in the juvenile composition between rainy and dry seasons. Despite the presence of representatives in the population during the dry months, rainy seasons encompassed 92.1% of juveniles sampled. The observed pattern of juveniles may be associated to biological factors (e.g. gametogenesis and life cycle) and abiotic (e.g. food supply and ocean currents). These results highlight the need for long-term monitoring programs that integrate ecological and abiotic elements to obtain a more complete understanding of the ecology of these worms and providing feedback for a better conservation of the marine biodiversity in the PEJX. KEYWORDS. Morphometric analysis, population dynamics, rocky shore, benthic invertebrates.RESUMO. Este estudo explora a maturação de gametas e biometria de Phragmatopoma caudata Krøyer in Mörch, 1863 para endossar uma metodologia e oferecer uma técnica adequada para estudos que objetivam avaliar a ecologia populacional. A análise de correlação de Pearson confirmou a relação positiva (r = 0,90, P <0,0001) entre o comprimento do corpo e o comprimento da coroa opercular. Indivíduos com opercular crown ≤ 0,9 mm podem ser considerados como juvenil devido à ausência de gametas. Portanto, utilizando-se o método aprovado para separar as classes de tamanho, a população dos recifes de P. caudata no Parque Estadual Xixová-Japuí (PEJX) na Baía de Santos, Estado de São Paulo, foi examinada durante dois anos, com o objetivo de analisar a densidade populacional e o padrão sazonal da classe juvenil. Em período de elevadas taxas de juvenis, a densidade populacional atingiu 128.115 ind./m 2 , porém, a média foi 65.090±22.033 ind./m 2 . As análises estatísticas (Kruskal-Wallis H = 18,475, p < 0,01) revelaram existir variação significativa na composição juvenil entre as estações chuvosa e seca. Apesar da presença de juvenis em mese...

Anterior sensory organs in Sabellariidae (Annelida)

“…Gregarious sabellariids, such as members of Gunnarea , Paraidanthyrsus, Sabellaria , Phragmatopoma, and Neosabellaria, are known to build large clumps or even large reefs in intertidal habitats, and therefore larvae seem to be able to detect conspecific individuals (Kirtley ; Bailey‐Brock et al. ; Faroni‐Perez ; Firth et al. ; Nishi et al.…”

“…; Desroy et al. ; Faroni‐Perez ; Firth et al ), but in other species individuals live in small clumps or are found as solitary individuals (Hutchings et al. ).…”

Phylogeography of the reef‐building polychaetes of the genus Phragmatopoma in the western Atlantic Region

“…Phragmatopoma caudata likely has large population sizes, as the density of individuals has been estimated at c . 65,000 individuals m − ² (Faroni‐Perez, ). Given that the generation time of P. caudata is of 1 year, a large fraction of individuals potentially contribute to the gene pool each year.…”

“…Phragmatopoma caudata (as P. lapidosa Kinberg, 1866) reproduces by external fertilization of gametes that are produced year‐round (Eckelbarger, ). Spawning and recruitment are highest in the summer months, from June to August in Florida, USA (McCarthy et al ., ), and February to April in São Paulo State, Brazil (Faroni‐Perez, ). Fecundity is high, as the average female can spawn 1500–2000 oocytes (McCarthy et al ., ).…”

Sabellariidae from Lizard Island, Great Barrier Reef, including a new species of Lygdamis and notes on external morphology of the median organ

“…Some species are gregarious and their cemented tubes form reef-like structures of hundreds to millions of individuals that can extend over several kilometres along the coast (e.g., Achari 1974;Kirtley 1974;Caline et al 1988Caline et al , 1992McCarthy et al 2008;Barrios et al 2009;Faroni-Perez 2014).…”