Distribuição espaço-temporal de poliquetas Nereididae, Capitellidae e Spionidae em planícies lamosas no complexo portuário-estuarino de Santos (SP) / Space and time distribution of polychaetes Nereididae, Capitellidae and Spionidae in muddy flats in Santos (SP) Port-estuarine complex

Estuários possuem relevante importância ecológica na zona costeira, abrigando comunidades bentônicas de expressivo papel na produtividade secundária. Efeitos de atividades antrópicas nestes ecossistemas podem ser evidenciados por meio de programas de monitoramento ambiental, os quais são aprimorados a partir da utilização de poliquetas, organismos susceptíveis a distúrbios. O conhecimento da distribuição destes invertebrados em planícies lamosas, incluindo seus padrões de zonação, se mostra fundamental para a elaboração de delineamentos amostrais eficientes. Desta forma, o presente trabalho objetivou investigar o padrão de zonação de três famílias de poliquetas (Nereididae, Spionidae e Capitellidae) em planícies lamosas do complexo portuário-estuarino de Santos (SP). Os organismos foram coletados em três zonas nas planícies lamosas: franja do infralitoral (ZI), porção intermediária do mesolitoral (ZM) e a franja do supralitoral (ZS). Os resultados evidenciaram um padrão de zonação, considerando as famílias Nereididae e Capitellidae, sendo que as assembleias variam seus padrões ao longo do tempo. Foi observado que a zona predominante destes organismos corresponde às porções superior e média da planície (ZS e ZM), sendo os mesmos encontrados em baixas densidades na porção inferior (ZI). Apenas a Família Spionidae não apresentou nenhum padrão de zonação, sendo sua distribuição variável ao longo do tempo. Nesse sentido, a presente contribuição traz evidências de que programas de monitoramento com coletas focadas na porção inferior das planícies lamosas podem não englobar satisfatoriamente as assembleias de Nereididae e Capitellidae. Tal fato deve ser considerado visando não comprometer a identificação precisa das variações nas comunidades macrobentônicas e, consequentemente, dos impactos antrópicos na região.(AU)

Estuaries have significant ecological importance in the coastal zone, sheltering macrobenthic communities with expressive role in secondary productivity. Effects of human activities in these ecosystems can be evidenced through environmental monitoring programs, which are improved by the use of polychaetes, organisms susceptible to variations. The knowledge about these invertebrates distribution in muddy flats, including their zonation patterns, is essential for the development of efficient sample designs. Thus, this study aimed to investigate the zonation pattern of three polychaetes families (Nereididae, Spionidae and Capitellidae) in muddy flats of Santos (SP) Port-estuarine complex. The organisms were collected in three areas in muddy flats: infratidal fringe (ZI), mesotidal intermediate portion (ZM) and supratidal fringe (ZS). The results showed a zonation pattern, considering the Nereididae and Capitellidae families. Assemblies vary their patterns over time. It was observed that the predominant area of these organisms correspond upper and middle of the flats (ZS and ZM), and they are found in low densities in the lower portion (ZI). Only the family Spionidae did not show any zonation pattern and its distribution was variable over time. In this sense, the present contribution brings evidences that monitoring programs focusing on sampling in the lower portion of muddy flats do not include satisfactorily the Nereididae and Capitellidae assemblies. This fact must be considered in order not to compromise the accurate identification of variations in the macrobenthic community and, consequently, of human impacts in the region.(AU)

Distribuição espaço-temporal de poliquetas Nereididae, Capitellidae e Spionidae em planícies lamosas no complexo portuário-estuarino de Santos (SP) / Space and time distribution of polychaetes Nereididae, Capitellidae and Spionidae in muddy flats in Santos (SP) Port-estuarine complex

Estuários possuem relevante importância ecológica na zona costeira, abrigando comunidades bentônicas de expressivo papel na produtividade secundária. Efeitos de atividades antrópicas nestes ecossistemas podem ser evidenciados por meio de programas de monitoramento ambiental, os quais são aprimorados a partir da utilização de poliquetas, organismos susceptíveis a distúrbios. O conhecimento da distribuição destes invertebrados em planícies lamosas, incluindo seus padrões de zonação, se mostra fundamental para a elaboração de delineamentos amostrais eficientes. Desta forma, o presente trabalho objetivou investigar o padrão de zonação de três famílias de poliquetas (Nereididae, Spionidae e Capitellidae) em planícies lamosas do complexo portuário-estuarino de Santos (SP). Os organismos foram coletados em três zonas nas planícies lamosas: franja do infralitoral (ZI), porção intermediária do mesolitoral (ZM) e a franja do supralitoral (ZS). Os resultados evidenciaram um padrão de zonação, considerando as famílias Nereididae e Capitellidae, sendo que as assembleias variam seus padrões ao longo do tempo. Foi observado que a zona predominante destes organismos corresponde às porções superior e média da planície (ZS e ZM), sendo os mesmos encontrados em baixas densidades na porção inferior (ZI). Apenas a Família Spionidae não apresentou nenhum padrão de zonação, sendo sua distribuição variável ao longo do tempo. Nesse sentido, a presente contribuição traz evidências de que programas de monitoramento com coletas focadas na porção inferior das planícies lamosas podem não englobar satisfatoriamente as assembleias de Nereididae e Capitellidae. Tal fato deve ser considerado visando não comprometer a identificação precisa das variações nas comunidades macrobentônicas e, consequentemente, dos impactos antrópicos na região.

Estuaries have significant ecological importance in the coastal zone, sheltering macrobenthic communities with expressive role in secondary productivity. Effects of human activities in these ecosystems can be evidenced through environmental monitoring programs, which are improved by the use of polychaetes, organisms susceptible to variations. The knowledge about these invertebrates distribution in muddy flats, including their zonation patterns, is essential for the development of efficient sample designs. Thus, this study aimed to investigate the zonation pattern of three polychaetes families (Nereididae, Spionidae and Capitellidae) in muddy flats of Santos (SP) Port-estuarine complex. The organisms were collected in three areas in muddy flats: infratidal fringe (ZI), mesotidal intermediate portion (ZM) and supratidal fringe (ZS). The results showed a zonation pattern, considering the Nereididae and Capitellidae families. Assemblies vary their patterns over time. It was observed that the predominant area of these organisms correspond upper and middle of the flats (ZS and ZM), and they are found in low densities in the lower portion (ZI). Only the family Spionidae did not show any zonation pattern and its distribution was variable over time. In this sense, the present contribution brings evidences that monitoring programs focusing on sampling in the lower portion of muddy flats do not include satisfactorily the Nereididae and Capitellidae assemblies. This fact must be considered in order not to compromise the accurate identification of variations in the macrobenthic community and, consequently, of human impacts in the region.

Levantamento de Polychaeta (Annelida) na Baía do Almirantado, Ilha Rei George (Antártica)

The Polychaeta collected during three distinct Brazilian Antarctic Expeditions (December 1996 to January-1997; December 1997 to January 1998; January to April 2001) in the Admiralty Bay have been studied. A total of 127 specimens have been examined and 18 species, belonging to 12 families, have been identified. The family Terebellidae was the most important family in number of species, and Terebellidae, Nephtyidae and Polynoidae in number of individuals. The species Terebellides longicaudatus and Aglaophamus trissophyllus were reported from the first time to the Bay and the genera Proclea (Terebellidae), Neanthes (Nereididae), Bradabyssa (Flabelligeridae), Euclymene (Maldanidae) were reported from the first time in the Martel Inlet.

Foram estudados os Polychaeta coletados durante três Expedições Oceanografcias brasilaeiras a Antarticia (Dezembro - 1996 a Janeiro - 1997; Dezembro - 1997 a Janeiro - 1998; Janeiro a Abril - 2001) para a Baia do Almirantado. Um total de 127 espécimes foi examinado e 18 espécies, pertencentes a 12 famílias, foram identificados. A família Terebellidae foi a que apresentou o maior número de espécies, e Terebellidae, Nephtyidae e Polynoidae apresentaram os maiores número de indivíduos coletados. As espécies Terebellides longicaudatus e Aglaophamus trissophyllus foram reportadas pela primeira vez na Baía e os gêneros Proclea (Terebellidae), Neanthes (Nereididae), Bradabyssa (Flabelligeridae), Euclymene (Maldanidae), foram reportados pela primeira vez na enseada de Martel.

Levantamento de Polychaeta (Annelida) na Baía do Almirantado, Ilha Rei George (Antártica)

The Polychaeta collected during three distinct Brazilian Antarctic Expeditions (December 1996 to January-1997; December 1997 to January 1998; January to April 2001) in the Admiralty Bay have been studied. A total of 127 specimens have been examined and 18 species, belonging to 12 families, have been identified. The family Terebellidae was the most important family in number of species, and Terebellidae, Nephtyidae and Polynoidae in number of individuals. The species Terebellides longicaudatus and Aglaophamus trissophyllus were reported from the first time to the Bay and the genera Proclea (Terebellidae), Neanthes (Nereididae), Bradabyssa (Flabelligeridae), Euclymene (Maldanidae) were reported from the first time in the Martel Inlet.

Foram estudados os Polychaeta coletados durante três Expedições Oceanografcias brasilaeiras a Antarticia (Dezembro - 1996 a Janeiro - 1997; Dezembro - 1997 a Janeiro - 1998; Janeiro a Abril - 2001) para a Baia do Almirantado. Um total de 127 espécimes foi examinado e 18 espécies, pertencentes a 12 famílias, foram identificados. A família Terebellidae foi a que apresentou o maior número de espécies, e Terebellidae, Nephtyidae e Polynoidae apresentaram os maiores número de indivíduos coletados. As espécies Terebellides longicaudatus e Aglaophamus trissophyllus foram reportadas pela primeira vez na Baía e os gêneros Proclea (Terebellidae), Neanthes (Nereididae), Bradabyssa (Flabelligeridae), Euclymene (Maldanidae), foram reportados pela primeira vez na enseada de Martel.

Morphological variations caused by fixation techniques may lead to taxonomic confusion in Laeonereis (Polychaeta: Nereididae)

The nereidid polychaete Laeonereis acuta (Treadwell, 1923) is either considered to be a valid species, or a synonym of Laeonereis culveri (Webster, 1879). The species epithet, acuta, refers to the acuminate anterior region of the body followed by a widening that is visible up to the 10th setiger. The relative width of the anterior region of the body, however, has been reported in the taxonomic literature as variable for Laeonereis Hartman, 1945, a genus known from the eastern coast of North America to Patagonia (southern South America). To test whether variations in this character are real, or whether they correspond to an artifact, we analyzed morphological changes associated with different anesthesia and fixation techniques regularly used to prepare specimens of Laeonereis from southern Brazil (formerly reported as L. acuta). Six treatments, including combinations of anesthetics and fixative agents, and a control, were evaluated in groups of 25 adult animals. A simple model II regression analysis on living specimens showed that the growth is approximately isometric. One-way ANOVA was used to compare the treatment effect on the ratio of peristome width: setiger 6 width. This ratio was smaller in non-anesthetized individuals, especially when prepared in formalin and freshwater. When anesthetized with menthol and fixed in formalin with sea water, individuals retained a shape that was closest to their in vivo shape. Consequently, our results suggest that fixation without prior anesthesia is not recommended for morphological and taxonomical studies. Since morphology and morphometrics of the anterior region are consistently influenced by preparation techniques, it is likely that inadequate fixation routines have introduced several errors in the taxonomic and ecological literature of Laeonereis.

Morphological variations caused by fixation techniques may lead to taxonomic confusion in Laeonereis (Polychaeta: Nereididae)

The nereidid polychaete Laeonereis acuta (Treadwell, 1923) is either considered to be a valid species, or a synonym of Laeonereis culveri (Webster, 1879). The species epithet, acuta, refers to the acuminate anterior region of the body followed by a widening that is visible up to the 10th setiger. The relative width of the anterior region of the body, however, has been reported in the taxonomic literature as variable for Laeonereis Hartman, 1945, a genus known from the eastern coast of North America to Patagonia (southern South America). To test whether variations in this character are real, or whether they correspond to an artifact, we analyzed morphological changes associated with different anesthesia and fixation techniques regularly used to prepare specimens of Laeonereis from southern Brazil (formerly reported as L. acuta). Six treatments, including combinations of anesthetics and fixative agents, and a control, were evaluated in groups of 25 adult animals. A simple model II regression analysis on living specimens showed that the growth is approximately isometric. One-way ANOVA was used to compare the treatment effect on the ratio of peristome width: setiger 6 width. This ratio was smaller in non-anesthetized individuals, especially when prepared in formalin and freshwater. When anesthetized with menthol and fixed in formalin with sea water, individuals retained a shape that was closest to their in vivo shape. Consequently, our results suggest that fixation without prior anesthesia is not recommended for morphological and taxonomical studies. Since morphology and morphometrics of the anterior region are consistently influenced by preparation techniques, it is likely that inadequate fixation routines have introduced several errors in the taxonomic and ecological literature of Laeonereis.

Morphological variations caused by fixation techniques may lead to taxonomic confusion in Laeonereis (Polychaeta: Nereididae)

The nereidid polychaete Laeonereis acuta (Treadwell, 1923) is either considered to be a valid species, or a synonym of Laeonereis culveri (Webster, 1879). The species epithet, acuta, refers to the acuminate anterior region of the body followed by a widening that is visible up to the 10th setiger. The relative width of the anterior region of the body, however, has been reported in the taxonomic literature as variable for Laeonereis Hartman, 1945, a genus known from the eastern coast of North America to Patagonia (southern South America). To test whether variations in this character are real, or whether they correspond to an artifact, we analyzed morphological changes associated with different anesthesia and fixation techniques regularly used to prepare specimens of Laeonereis from southern Brazil (formerly reported as L. acuta). Six treatments, including combinations of anesthetics and fixative agents, and a control, were evaluated in groups of 25 adult animals. A simple model II regression analysis on living specimens showed that the growth is approximately isometric. One-way ANOVA was used to compare the treatment effect on the ratio of peristome width: setiger 6 width. This ratio was smaller in non-anesthetized individuals, especially when prepared in formalin and freshwater. When anesthetized with menthol and fixed in formalin with sea water, individuals retained a shape that was closest to their in vivo shape. Consequently, our results suggest that fixation without prior anesthesia is not recommended for morphological and taxonomical studies. Since morphology and morphometrics of the anterior region are consistently influenced by preparation techniques, it is likely that inadequate fixation routines have introduced several errors in the taxonomic and ecological literature of Laeonereis.

Nereididae (Annelida, Polychaeta) da costa nordeste do Brasil: II. Gêneros Namalycastis, Ceratocephale, Laeonereis e Rullierinereis

Six polychaete species belonging to the genera Namalycastis Hartman, 1959, Ceratocephale Malmgren, 1867, Laeonereis Hartman, 1945, and Rullierinereis Pettibone, 1970 were recorded as part of a systematic survey of the family Nereididae in estuaries, exposed sandy beaches, shelly soft bottoms, atolls and coral reefs of the Brazilian northeastern coast. Two new species, Rullierinereis auxiliadorae, from Ceará coast and Ceratocephale rocaensis, from Atol das Rocas, are described.

Nereididae (Annelida, Polychaeta) da costa nordeste do Brasil: II. Gêneros Namalycastis, Ceratocephale, Laeonereis e Rullierinereis

Six polychaete species belonging to the genera Namalycastis Hartman, 1959, Ceratocephale Malmgren, 1867, Laeonereis Hartman, 1945, and Rullierinereis Pettibone, 1970 were recorded as part of a systematic survey of the family Nereididae in estuaries, exposed sandy beaches, shelly soft bottoms, atolls and coral reefs of the Brazilian northeastern coast. Two new species, Rullierinereis auxiliadorae, from Ceará coast and Ceratocephale rocaensis, from Atol das Rocas, are described.

Nereididae (Annelida, Polychaeta) da costa nordeste do Brasil: II. Gêneros Namalycastis, Ceratocephale, Laeonereis e Rullierinereis

Six polychaete species belonging to the genera Namalycastis Hartman, 1959, Ceratocephale Malmgren, 1867, Laeonereis Hartman, 1945, and Rullierinereis Pettibone, 1970 were recorded as part of a systematic survey of the family Nereididae in estuaries, exposed sandy beaches, shelly soft bottoms, atolls and coral reefs of the Brazilian northeastern coast. Two new species, Rullierinereis auxiliadorae, from Ceará coast and Ceratocephale rocaensis, from Atol das Rocas, are described.

Nereididae (Polychaeta) da costa nordeste do Brasil: III. Gêneros Ceratonereis e Nereis

Ten species belonging to the genera Ceratonereis Kinberg, 1866 and Nereis Linnaeus, 1758 were recorded in estuaries, exposed sandy beaches, shelly soft bottoms, atolls and coral reefs of the Brazilian northeastern coast. Two new species, Nereis serrata, from Ceará coast, and Nereis pseudomoniliformis, from Sergipe coast, are described.

Nereididae (Polychaeta) da costa nordeste do Brasil: III. Gêneros Ceratonereis e Nereis

Ten species belonging to the genera Ceratonereis Kinberg, 1866 and Nereis Linnaeus, 1758 were recorded in estuaries, exposed sandy beaches, shelly soft bottoms, atolls and coral reefs of the Brazilian northeastern coast. Two new species, Nereis serrata, from Ceará coast, and Nereis pseudomoniliformis, from Sergipe coast, are described.