Fouling organisms on Perna perna mussels: is it worth removing them?

Perna perna mussel spat were suspended from ropes on a long-line cultivation, at Coqueiro´s Beach, Anchieta, South-eastern Brazil, in order to quantify the fouling community structure and its effects on growth and biomass of mussels. Half of the ropes had the fouling removed monthly, half had the foulingleft until the end of the experiment. Monthly samples of thirty mussels from each group were measured and their biomass determined. The fouling organisms were identified, quantified and their biomass evaluated on a monthly basis. After ten months, mussels on the cleaned treatment were significantly larger and heavier (ANOVA; P ; fouled), showing that fouling reduced mussel development. The most abundant epibiont organisms in terms of biomass were the algae Polysiphonia subtilissima (29%) and Ulva rigida (10.3%), followed by the bryozoans Bugula neritina (13.6%) and Perna perna spat (10.6%). Over 97 taxa and 42,646 individuals were identified, crustaceans being the most abundant group, predominantly one amphipod Cheiriphotis megacheles (12,980 ind.). Species abundance was positively correlated with algal biomass, revealing the influence of algae on vagile fauna, which provide both food and shelter. The benefits of fouling removal are discussed because the majority of species are important feeding items to fishes and yet, the costs of its fouling control added to the associated mussel spat loss make this fouling removal of questionable value.Sementes de Perna perna foram colocadas em cordas suspensas em long-line na Praia do Coqueiro, Anchieta, ES, objetivando-se determinar a estrutura da comunidade de incrustantes e seu efeito sobre o desenvolvimento dos mexilhões. Metade das cordas teve os incrustantes removidos mensalmente, na outra metade eles foram deixados até o final do experimento. Mensalmente, 30 mexilhões de cada grupo foram retirados e medidos e a biomassa aferida. Os incrustantes foram identificados, quantificados e a biomassa de cada taxon determinada. Após 10 meses de cultivo, os mexilhões sem incrustantes eram significativamente maiores e mais pesados (ANOVA; P ; com incrustantes), demonstrando que os incrustantes interferiram negativamente no desenvolvimento dos mexilhões. Os incrustantes mais abundantes em termos de biomassa foram as algas Polysiphonia subtilissima (29%) e Ulva rigida (10,3%), seguidas pelos briozoários Bugula neritina (13,6%) e sementes de Perna perna (10,6%). Foram registrados 97 taxa e 42.646 indivíduos, sendo Crustacea o grupo mais abundante, principalmente o anfípodo Cheiriphotis megacheles (12.980 ind.). A abundância de indivíduos foi positivamente correlacionada com a biomassa de algas, revelando a influência das algas na fauna vágil, provendo abrigo e alimentação. Os benefícios da remoção dos incrustantes são discutidos, uma vez que a maioria dos incrustantes são importantes como itens alimentares para os peixes; além disso, os custos desta remoção somados à perda de sementes de mexilhões, tornam a remoção desta comunidade de incrustantes questionável

Soft-Bottom macrobenthic communities of the Vitória Bay estuarine system, South-eastern Brazil

O presente trabalho analisa e descreve a estrutura das associações faunísticas macrobênticas (epifauna e infauna) do sistema estuarino da Baía de Vitória, sudeste do Brasil, de Janeiro de 1998 a Junho de 1999. Amostras replicadas em níveis de entre-marés e sublitoral foram coletadas em intervalos de três meses em dez estações. Foram caracterizadas as composições dos sedimentos de entre-marés e sublitoral. Os parâmetros físico-químicos da água foram medidos in situ. Foram coletados 10.695 indivíduos, compreendendo a 144 taxa. Os grupos mais abundantes foram moluscos, crustáceos e poliquetos. As espécies mais abundantes foram os bivalves Anomalocardia brasiliana, Mytella guyanensis e M. falcata. Localmente, descargas significativas de esgoto doméstico causaram um aumento da quantidade de matéria orgânica no sedimento (até 30%) e baixa concentração de oxigênio dissolvido na água (< 1mg.l-1). Próximo às duas entradas da baía, o alto hidrodinamismo e a presença de areia grossa reduziram os efeitos deletérios dos aportes de esgotos. A riqueza (S), a diversidade (H') de espécies e a abundância total (A), decresceram das estações externas do estuário (22 < S < 72; 1.99 < H' < 2.85; 320 < A < 1737) em direção às estações internas (2 < S < 45; 0.59 < H' < 2.67; 2 < A < 1317), onde a salinidade e oxigênio dissolvido foram menores e as quantidades de matéria orgânica maiores.The present work describes and analyses the structure of the macrobenthic epi- and infaunal assemblage of the estuarine system of Vitória Bay, South-eastern Brazil, from January 1998 to June 1999. Replicated sampling at intertidal and subtidal levels was conducted quarterly at ten stations. Intertidal and subtidal sediment composition was characterised. Water physico-chemical parameters were measured in situ. A total of 10,695 individuals, belonging to 144 taxa, were collected. Molluscs, crustaceans and polychaetes were the most abundant groups. The bivalves Anomalocardia brasiliana, Mytella guyanensis and M. falcata were the most abundant species. Locally, significant discharges of residential and industrial wastewater resulted in high organic content in the sediment (up to 30%) and low dissolved oxygen concentration in the water (< 1mg.l-1). Near the two entrances of the bay, high hydrodynamic activity and coarse sand reduced the detrimental effects of raw and treated sewage inputs. Species richness (S), diversity (H') and total abundance (A) decreased from outer-bay stations (22 < S < 72; 1.99 < H' < 2.85; 320 < A < 1737) towards inner-bay stations (2 < S < 45; 0.59 < H' < 2.67; 2 < A < 1317), where salinity and dissolved oxygen were lowest and organic matter content highest

Oyster spat recruitment in Espírito Santo State, Brazil, using recycled materials

Este trabalho avaliou a eficiência de quatro tipos de coletores de sementes no recrutamento de ostras Crassostrea sp., em cinco pontos do estuário do Rio Benevente, município de Anchieta, e em duas ilhas no município de Piúma, estado do Espírito Santo. Foram utilizados quatro tipos de coletores: 1-conchas de ostras, 2- garrafas PET, 3-tiras de pneu e 4- telhas, todos suspensos por cordas e amarrados em rizóforos de Rhizophora mangle ou em "long-lines" de mexilhões. Bimensalmente, as sementes recrutadas foram contadas e medidas quanto à altura, determinando-se os parâmetros físico-químicos-tróficos da água: salinidade, temperatura, oxigênio dissolvido, matéria orgânica particulada e clorofila-a, que foram correlacionados com o número de sementes nos coletores (através de correlações de Spearman). O recrutamento de sementes foi significativamente maior nos coletores de conchas de ostras, telhas e pneus, principalmente nos pontos de salinidade mais alta (Praia do Coqueiro em Anchieta e Ilhas do Meio e do Cabrito em Piúma) (Kruskal-Wallis: H= 10,01; 3 g.l.; P ;0,05). O número de sementes de ostras foi positivamente correlacionado com a salinidade (&#961;s= 0,331; P ; 0.05). The number of oyster spat was positively correlated with the salinity (&#961;s= 0.331; p < 0.05) and water temperature (&#961;s= 0.48; p < 0.05), revealing that areas with higher salinities and summer months were better for spat collection

Polydora rickettsi Woodwick 1961

&lt;i&gt;Polydora rickettsi&lt;/i&gt; Woodwick, 1961 &lt;p&gt; &lt;i&gt;Polydora rickettsi&lt;/i&gt; Woodwick (1961, pp. 78&ndash;81, Figs 1&ndash;7). &mdash; Blake (1983, p. 257). &mdash; Radashevsky &amp; C&aacute;rdenas (2004, pp. 244&ndash;252, Figs 2&ndash;6).&lt;/p&gt; &lt;p&gt; ? &lt;i&gt;Polydora&lt;/i&gt; sp. II: Carrasco (1976, pp. 34&ndash;37, Figs 12, 13 L&ndash;O, 21C).&lt;/p&gt; &lt;p&gt; &lt;i&gt;Polydora&lt;/i&gt; sp.: Bas&iacute;lio, Ca&ntilde;ete &amp; Rozbaczylo (1995, pp. 72&ndash;74, Fig. 1 A&ndash;H).&lt;/p&gt; &lt;p&gt; &lt;i&gt;Polydora&lt;/i&gt; cf. &lt;i&gt;rickettsi&lt;/i&gt;: Sato-Okoshi &amp; Takatsuka (2001, pp. 489&ndash;490, Fig. 2 A&ndash;D).&lt;/p&gt; &lt;p&gt; &lt;i&gt;Adult morphology (based on material from Brazil)&lt;/i&gt;&lt;/p&gt; &lt;p&gt;Specimens in poor condition. Up to 15 mm long and 0.6 mm wide at chaetiger 7 for 130 chaetigers. Black pigment diffused on palps along longitudinal ciliated grove, on sides of prostomium and on 1&ndash;4 anterior chaetigers; present only on prostomium or absent in some specimens. Largest individual with 130 chaetigers and with black bands on palps. Prostomium blunt to rounded anteriorly. Caruncle extending to middle of chaetiger 3. Occipital antenna absent. One to four eyes present or eyes absent.&lt;/p&gt; &lt;p&gt;Chaetiger 1 with short capillaries in neuropodia and postchaetal lamellae in both rami; notochaetae absent. Posterior notopodia with only capillary chaetae.&lt;/p&gt; &lt;p&gt;Chaetiger 5 greatly modified, with 2&ndash;3 dorsal superior capillaries, 4&ndash;6 major spines alternating with bilimbate-tipped companion chaetae, and ventral tuft of 4&ndash;6 capillaries; postchaetal lamellae absent. Dorsal superior and ventral capillaries shorter and fewer than those on chaetigers 4 and 6. Major spines falcate, with lateral tooth and narrow longitudinal flange located laterally on main fang above accessory tooth.&lt;/p&gt; &lt;p&gt;Branchiae from chaetiger 7 to almost end of body, full-sized from chaetiger 10&ndash;11, greatly diminishing on posterior chaetigers.&lt;/p&gt; &lt;p&gt;Hooks in neuropodia from chaetiger 7, bidentate, with constriction on shaft, up to 9 in a series.&lt;/p&gt; &lt;p&gt;Pygidium small, cup-shaped to disc-like with dorsal incision.&lt;/p&gt; &lt;p&gt;Gizzard-like structure in digestive tract not distinguished.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Remarks&lt;/i&gt;&lt;/p&gt; &lt;p&gt; &lt;i&gt;Polydora rickettsi&lt;/i&gt; was originally described by Woodwick (1961) as associated with calcareous tubes of the serpulid polychaete &lt;i&gt;Spirobranchus incrassatus&lt;/i&gt; M&ouml;rch from Lower California, Mexico. Sato-Okoshi &amp; Takatsuka (2001) reported &lt;i&gt;P.&lt;/i&gt; cf. &lt;i&gt;rickettsi&lt;/i&gt; boring into shells of the oysters &lt;i&gt;Crassostrea gigas&lt;/i&gt; and &lt;i&gt;Ostrea chilensis&lt;/i&gt; (Philippi, 1845) in southern Chile. The worms resided in U-shaped burrows within the shells. More than 50 worms were found in one oyster shell, and 1&ndash;2 worms per cm2 were found on the shell surface (Sato-Okoshi &amp; Takatsuka 2001). Radashevsky &amp; C&aacute;rdenas (2004) also described adult and larval morphology of the species from Chile and indicated that identification of the Chilean worms should be verified by further studies on specimens from Mexico.&lt;/p&gt; &lt;p&gt; In Brazil, worms were found in a shell of the scallop &lt;i&gt;Nodipecten nodosus&lt;/i&gt; (Linnaeus, 1758). The scallop was collected off the coast of the state of S&atilde;o Paulo and maintained for a long time in an aquarium of the University of S&atilde;o Paulo (USP). The fixed scallop shell with worms was received for examination from Jo&atilde;o M. de M. Nogueira in 2001. Specimens from Brazil appear similar to &lt;i&gt;P. rickettsi&lt;/i&gt; from Chile. Both have an entire prostomium, characteristic falcate spines on chaetiger 5, and a small disc-like pygidium. The only difference is that the largest specimen (with 130 chaetigers) from Brazil has black bands on the palps and black pigment on the sides of the prostomium. Worms from Mexico and Chile (largest with 125 chaetigers) have no such pigmentation on palps. The presence of black bars or bands on palps is a diagnostic feature appearing stable in some species (e.g., &lt;i&gt;Polydora brevipalpa&lt;/i&gt; Zachs, 1933) and variable in others (e.g., &lt;i&gt;P. ecuadoriana&lt;/i&gt;, &lt;i&gt;P. h a s w e l l i&lt;/i&gt;, &lt;i&gt;P. neocaeca&lt;/i&gt;). Further studies are needed to verify the identification of worms boring in &lt;i&gt;N. nodosus&lt;/i&gt; in Brazil.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Distribution&lt;/i&gt;&lt;/p&gt; &lt;p&gt;Pacific Mexico; Chile;? Brazil: S&atilde;o Paulo.&lt;/p&gt;Published as part of &lt;i&gt;Radashevsky, Vasily I., Lana, Paulo C. &amp; Nalesso, Rosebel C., 2006, Morphology and biology of Polydora species (Polychaeta: Spionidae) boring into oyster shells in South America, with the description of a new species, pp. 1-37 in Zootaxa 1353&lt;/i&gt; on pages 22-24, DOI: &lt;a href="http://zenodo.org/record/174538"&gt;10.5281/zenodo.174538&lt;/a&gt

Polydora carinhosa Radashevsky, Lana & Nalesso, 2006, sp. nov.

Polydora carinhosa sp. nov. (Figs 10–12) Material Paraná, Paranaguá Bay, 25 ° 28´S, 48 ° 27´W, 2 m, from shells of the oyster C. rhizophorae, 13 Sep 2001, coll. V.I. Radashevsky, MZSP 182 (holotype). Santa Catarina, Florianópolis, Praia da Ponta de Sambaqui, 27 °28.5´S, 48 °33.7´W, 1 m, from shells of the cultured oyster C. gigas, coll. Y.M.B. Neptune, 25 Apr 2003, MZSP 181 (1 paratype). Adult morphology Holotype complete male, with 103 chaetigers; paratype anterior fragment of female. Prostomium rounded anteriorly. One pair of black eyes present in holotype; eyes absent in paratype. Caruncle extending to middle of chaetiger 3. Occipital antenna absent. Black pigment diffused on dorso-lateral sides of peristomium, in front of palp bases, and on dorsal side of four anterior chaetigers; segmental patches of pigment larger on anterior chaetigers (Fig. 10 A). Narrow black line present along longitudinal ciliated groove on palps. Chaetiger 1 with short capillaries in neuropodia and small postchaetal lamellae in both rami, notochaetae absent. Posterior notopodia with packets of needle-like spines besides capillaries. Needles not protruding beyond body surface, beginning from chaetiger 27 in holotype. Chaetiger 5 greatly modified, with 4 dorsal superior winged capillaries (Fig. 10 C), 6 major modified spines alternating with bilimbate-tipped companion chaetae and arranged in a slightly curved, diagonal row (Fig. 10 D), and 6 winged ventral capillaries (Fig. 10 B); postchaetal lamellae absent. Dorsal superior and ventral capillaries shorter and fewer than those on chaetigers 4 and 6. Major spines falcate, with small lateral accessory tooth. Hooded hooks in neuropodia from chaetiger 7, bidentate, with constriction on shaft. Branchiae on chaetigers 7–90, full-sized from chaetiger 11. Nototrochs from chaetiger 7 onwards (Fig. 10 A). Pygidium small, cup-shaped. Holotype male, with sperm first present in chaetiger 27. Habitat Polydora carinhosa bores in shells of the oysters C. rhizophorae and C. gigas. Reproduction Polydora carinhosa is gonochoristic. Females deposit eggs into capsules which are joined to each other in a string. Each egg capsule is attached by two thin stalks to the inner wall of the burrow. Larvae develop inside the capsules until about the 14 -chaetiger stage. The kind of lecithotrophy (endo- or exolecithotrophy) in P. carinhosa is unknown since only two broods with 10 - and 13–14 -chaetiger larvae were found. Larval development Ten-chaetiger larvae (Fig. 11 A) about 650 µm long, with three pairs of black eyes including two pairs of lateral eyes and one pair of median eyes; lateral eyes positioned close to each other and obscured by ramified melanophores positioned above them. Prostomium and peristomium weakly demarcated. A group of short non-motile apical cilia present on frontal edge of prostomium. Lateral lips of peristomium well developed, forming a voluminous vestibulum lined with short fine cilia. Vestibular ciliation running posteriorly over low ventral peristomial lip as a triangular neurotroch. One pair of small ciliated cells positioned on either side of neurotroch in the middle of chaetiger 1. Prototroch formed by two bands of long cilia running along lateral sides of peristomium, and two shorter bands of shorter cilia running across lateral lips of peristomium. Short compound cilia positioned along outer edges of vestibulum; these cirri probably sensory, moving slower than simple cilia. Nototrochs from chaetiger 3 onwards. Grasping cilia on either side of each nototroch, beating perpendicular to body axis and holding long bristles along the dorsum when larva is swimming in the capsule. Gastrotrochs on chaetigers 3, 5, 7, and 10. Telotroch interrupted middorsally, forming a gap where long bristles are held when larva is swimming in the capsule. Fine grains of yellow pigment dispersed on anterior part of prostomium, on ventral side of posterior chaetigers and on pygidium. A pair of ramified melanophores present on prostomium between median and lateral eyes. A pair of small melanophores on ventral side of lateral peristomial lips, just on prototroch level. Black pigment present laterally between chaetigers 1 and 2. Distinct transverse paired melanophores on dorsal side of chaetigers 3–6, in front of nototrochs; from chaetiger 7 those melanophores becoming stellar, ramified. Paired black pigmentation present on dorsal sides of pygidium. Larval serrated bristles in all notopodia, those on chaetiger 1 longest. Voluminous vestibulum opening posteriorly into short esophagus which extends to end of chaetiger 2. Buccal bulb absent. A muscular sphincter present between esophagus and stomach. The stomach narrowing posteriorly and weakly separated from the hindgut. Wall of the stomach containing numerous oil drops; its inner surface lined with fine cilia. Two pairs of protonephridia in chaetigers 1 and 2. Fully developed, ready to hatch larvae 800–850 µm long for 13–14 chaetigers. Fine granules of yellow pigment dispersed on anterior part of prostomium, on pygidium, and on ventral side from chaetiger 6 (Fig. 12 C). Two large black patches on dorsal side of pygidium, along edge of gap; no middorsal melanophore. Short single motile cilia on tips of postchaetal lamellae. Numerous non-motile sensory cilia on frontal edge of prostomium, on palps and on posterior edge of pygidium. One pair of banana-shaped cells with striated contents positioned posterior to median eyes; large fusiform cells with striated contents positioned inside anterior end of prostomium and in palps; elongated cells of irregular shape present on dorsal and ventral sides of chaetigers, and inside pygidium. Gastrotrochs on chaetigers 3, 5, 7, 10, and 13. Those on chaetigers 3 and 5 composed of two lateral ciliated cells, those on other chaetigers with five ciliated cells. Chaetiger 5 with 2 dorsal superior capillaries (Fig. 11 E), 4 dorsal modified chaetae (Fig. 11 F–H) and 3 ventral capillaries (Fig. 11 D). Modified chaetae including first two provisional spines and posterior two chaetae of quasi-adult type. Provisional spines including one heavy falcate spine with longitudinal groove (Fig. 11 G), and one thinner, awl-like spine with sigmoid distal end (Fig. 11 F); chaetae of quasi-adult type including heavy falcate spines with two lateral teeth, and bilimbate-tipped companion chaetae (Fig. 11 H). Hooded hooks in neuropodia from chaetiger 7, 2 – 3 in a series, accompanied by 2–3 winged capillaries (Fig. 11 B,C). Lateral organs as small pits 3–5 µm in diameter with stiff, non-motile cilia 10–15 µm long between noto- and neuropodia on all chaetigers. Glandular pouches in chaetigers 6–11, large in anterior chaetigers and gradually diminishing in size posteriorly, each composed of 1–2 large secretory cells enveloped by thin common membrane but opening to the exterior separately. Circulatory system developed and functional. Protonephridia in chaetigers 1 and 2. Metanephridia from chaetiger 7 onwards. Settlement and metamorphosis Larvae of P. carinhosa underwent gradual metamorphosis and loss of provisional larval features inside the egg capsules when they grown to 900 µm long for 14 chaetigers. The largest larva without bristles in notopodia was 1035 µm long for 14 chaetigers. The 14 -chaetiger larvae hatched and settled after a short planktonic stage (Fig. 13). Adult mode of feeding after settlement was enabled by rapid elongation of the palps, modification of the prostomium, enlargement of the ventral peristomial lip and transformation of the lateral peristomial lips into dorso-lateral ciliary folds. In further development, the prostomium became separated from the peristomium; the caruncle and nuchal ciliated bands elongated posteriorly over chaetiger 3, and nototrochs were lost on anterior chaetigers. Remarks Five Polydora species, besides P. carinhosa, have been described with needle-like spines in posterior notopodia. Those include P. aura Sato-Okoshi, 1998 from Japan, P. latispinosa from Australia, P. f u s c a Radashevsky & Hsieh, 2000 and P. v i l l o s a Radashevsky & Hsieh, 2000 from Taiwan (see Radashevsky & Hsieh 2000: table 2), and Polydora robi Williams, 2000 from Philippines and Indonesia. The spines in P. f u s c a, P. robi and P. v i l l o s a are separate and greatly protrude through the cuticle, whereas in P. aura, P. carinhosa and P. latispinosa they are gathered into tight packets and do not protrude through the cuticle. Polydora aura, P. f u s c a, P. latispinosa and P. ro b i differ from this new species in having an occipital antenna on the caruncle. Also, these four species have no dorsal superior capillaries on chaetiger 5, whereas those chaetae are present in P. carinhosa and P. v i l l o s a. Polydora fusca inhabits mud tubes on soft bottom; P. v i l l o s a bores in corals, while P. aura, P. carinhosa, P. latispinosa and P. ro b i bore in shells of various mollusks. Polydora carinhosa and P. ro b i differ from other needle-bearing species in having an entire prostomium instead of a prostomium with a weak incision on the anterior margin. Polydora robi is unique among these species in having a pygidium surrounded by anal papillae, without a cup-shaped or disk-like expansion. Polydora carinhosa is also remarkable in that the larval development is completed entirely in the egg capsules inside the mother’s tube, and larvae settle shortly after hatching. Among Polydora species, benthic lecithotrophic development was also described in P. c u r i o s a, P. hoplura and P. nuchalis Woodwick, 1953. In P. c u r i o s a, females deposit a few large eggs in each capsule, all of which develop into larvae (endolecithotrophy) (Radashevsky 1994). In P. hoplura and P. nuchalis, females deposit many small eggs, few of which develop into larvae engulfing non-developing nurse eggs (adelphophagia or exolecithotrophy) (Wilson 1928; Woodwick 1953, 1960). The kind of lecithotrophy in P. carinhosa is unknown since only two broods with developed larvae were found. Development of temporary, long serrated bristles in notopodia of the larvae suggests that adelphophagia probably occurs in this species. Distribution Brazil: Paraná south to Santa Catarina.Published as part of Radashevsky, Vasily I., Lana, Paulo C. & Nalesso, Rosebel C., 2006, Morphology and biology of Polydora species (Polychaeta: Spionidae) boring into oyster shells in South America, with the description of a new species, pp. 1-37 in Zootaxa 1353 on pages 25-30, DOI: 10.5281/zenodo.17453

Polydora Bosc 1802

Polydora Bosc, 1802 Polydora species boring into oyster shells in South America 1. Polydora ecuadoriana Blake, 1983 2. Polydora cf. haswelli Blake & Kudenov, 1978 3. Polydora rickettsi Woodwick, 1961 4. Polydora carinhosa sp. nov.Published as part of Radashevsky, Vasily I., Lana, Paulo C. & Nalesso, Rosebel C., 2006, Morphology and biology of Polydora species (Polychaeta: Spionidae) boring into oyster shells in South America, with the description of a new species, pp. 1-37 in Zootaxa 1353 on page 6, DOI: 10.5281/zenodo.17453

Polydora haswelli Blake & Kudenov 1978

Polydora cf. haswelli Blake & Kudenov, 1978 (Figs 8 & 9) Polydora haswelli Blake & Kudenov (1978, pp. 259–260, Fig. 44). Polydora websteri: Bolívar & Lana (1987, pp. 115–116, Figs 8 –20). — Blankensteyn & Moura (2002, p. 718, table 2). Not Polydora websteri Hartman in Loosanoff & Engle, 1943. Material BRAZIL, Espírito Santo: Espírito Santo Bay: Ilha do Frade, 20 ° 17´S, 40 ° 17´W, intertidal, from shells of the oyster C. rhizophorae, coll. R.C. Nalesso and V.I. Radashevsky, 29 May 2003, MZSP 175 (12); 25 Feb 2004, MZSP 310 (5). São Paulo: Alcatrazes Is., 24 °06´S, 45 ° 42´W, 5–6 m, from live stony coral Mussismilia hispida (Verrill, 1808), coll. J.M.M. Nogueira, 4 Dec 1996, MZSP 173 (2), USNM 1022188 (2). Praia Fazenda, 23 ° 22´S, 44 °50.3´W, intertidal, sandy beach, from shell of a gastropod inhabited by hermit crab Dardanus insignis (de Saussure, 1858), 0 9 May 2001, coll. V.I. Radashevsky, MZSP (1 +). Praia São Francisco, 23 ° 45´S, 45 ° 25´W, intertidal, from shells of living oysters and gastropods, and from gastropods inhabited by hermit crabs, 16 Apr 2003, coll. V.I. Radashevsky, MZSP (1 +). Praia Araçá, 23 °48.8´S, 45 °24.2´W, sandy intertidal, coll. V.I. Radashevsky, from shell of oyster C. rhizophorae, 17 Apr 2003, MZSP (1 +). São Sebastião Island, Praia do Curral, 23 °51.5´S, 45 °25.9´W, 3–5 m, from empty shells of the gastropod Stramonita haemastoma inhabited by hermit crabs, 13 May 2004, coll. V.I. Radashevsky, (10 +, notes on live material, not fixed). São Sebastião, Praia do Saco Grande, 23 °49.7´S, 45 °25.5´W, 1–5 m, from shells of living saddle oyster Anomia ephippium Linnaeus, 1758 and gastropods Astraea olfersii (Philippi, 1846), Morula nodulosa (Adams, 1845), Pisania auritula (Link, 1807), Pisania pusio (Linnaeus, 1758), Siratus senegalensis (Gmelin, 1791), Stramonita haemastoma, Strombus pugilis, and Tegula viridula inhabited by hermit crabs Paguristes tortugae and Pagurus brevidactylus, 30 Jun 2004, coll. V.I. Radashevsky, MZSP 179 (50). Paraná: Paranaguá Bay: Ilha das Cobras, 25 °28.9´S, 48 ° 26´W, intertidal, from oyster shell, 23 Jul 1985, coll. P.C. Lana, CEM/ UFPR 38 (2). Brasilia village of Ilha do Mel, 25 ° 33´S, 48 ° 19´W, 0.5 m, 25 Aug 2001, coll. V.I. Radashevsky, from shell of the gastropod Crepidula plana Say, 1822, MZSP 178 (1); from shells of gastropods Pugilina morio and Stramonita haemastoma inhabited by hermit crab Clibanarius vittatus, MZSP 176 (80). 25 ° 28´S, 48 ° 27´W, 2 m, from shells of the cultured oyster C. rhizophorae, 13 Sep 2001, coll. V.I. Radashevsky, MZSP 174 (10). Santa Catarina, Florianópolis: Praia da Ponta de Sambaqui, 27 °28.5´S, 48 °33.7´W, 1 m, from shells of the cultured oyster C. gigas, coll. Y.M.B. Neptune, 15 Aug 2003, MZSP 177 (18). Adult morphology Up to 30 mm long and 1 mm wide at chaetiger 7 for 170 chaetigers. Body pale or light tan in life. Pigmentation on palps greatly variable: fine black lines or separate black bars present along longitudinal ciliated groove; occasionally pigmentation lacking. Pigment pattern and numbers of bars on palps not correlated with total number of chaetigers in an individual. Light yellow pigment often present along ciliated groove between black bars. Black pigment absent on body or black narrow strips present on either side of anterior part of prostomium, and indistinct paired patches present on dorsal side of peristomium and 1–3 anterior chaetigers. Small distinct yellow chromatophores present on dorso-lateral sides of posterior chaetigers in large individuals (Fig. 8 E). Yellow pigment on palps and posterior chaetigers absent in formaldehyde-fixed specimens. Prostomium incised anteriorly. Caruncle extending to end of chaetiger 3. Occipital antenna absent. Two pairs of black eyes usually present; occasionally one to three eyes present or eyes lacking. Palps as long as 10–20 chaetigers, with longitudinal groove lined with fine frontal cilia, latero-frontal motile compound cilia bordering groove, short lateral papillae with non-motile cirri arranged along either side of groove, and short compound non-motile cilia arising directly from palp surface and scattered on lateral and abfrontal palp surfaces. Chaetiger 1 with short capillaries in neuropodia and postchaetal lamellae in both rami; notochaetae absent. Posterior notopodia with only capillary chaetae. Chaetiger 5 greatly modified, almost twice as large as chaetigers 4 or 6, with 3–5 dorsal superior winged capillaries (Fig. 8 C), 5–8 major modified spines alternating with bilimbate-tipped companion chaetae and arranged in a slightly curved, diagonal row, and 5–8 winged ventral capillaries (Fig. 8 B); postchaetal lamellae absent. Dorsal superior and ventral capillaries shorter and fewer than those on chaetigers 4 and 6. Major spines falcate, with lateral accessory flange of variable size (Fig. 8 D). Hooded hooks in neuropodia from chaetiger 7, bidentate, with constriction on shaft (Fig. 8 A), up to 8 in a series. Branchiae from chaetiger 7, full-sized from chaetigers 9–10, distributed to middle or usually almost end of body, becoming much smaller on posterior chaetigers. Pygidium cup-shaped to disc-like, with dorsal gap to narrow incision, white due to numerous glandular cells; small notch often present on ventral side of pygidium, usually positioned asymmetrically (Fig. 8 E). Small knobs with short non-motile, probably sensory, cilia arranged along edge of pygidium, mainly along its dorso-lateral edge. Lateral ciliated organs as small pits between noto- and neuropodia on all chaetigers except 4 and 5. Glandular pouches from chaetiger 7, large in chaetigers 7 to 9, then greatly diminishing in size. Digestive tract without gizzard-like structure. Metanephridial segmental organs from chaetiger 7, opening to exterior laterally on anterior, sterile chaetigers and dorsally on gametogenic chaetigers; paired nephridia opening separately on all chaetigers. Habitat In Brazil, P. cf. haswelli was found intertidally and in shallow water in shells of live oysters Crassostrea brasiliana, C. gigas, C. rhizophorae and Anomia ephippium, the gastropod Crepidula plana, and empty shells of the gastropods Astraea olfersii, Pisania auritula, Pisania pusio, Pugilina morio, Siratus senegalensis, Stramonita haemastoma, Strombus pugilis, and Tegula viridula inhabited by hermit crabs Clibanarius vittatus, Paguristes tortugae and Pagurus brevidactylus, and also in live scleractinian corals. Up to 10 worms occurred per cm 2 of shell surface. Worm burrows were U-shaped with walls lined with fine silt. The burrows of P. cf. haswelli resemble those of P. ecuadoriana. The two species occurred together in shells in various proportions. Reproduction Polydora cf. haswelli is gonochoristic. Spermatids were interconnected in tetrads. Spermatozoa were introsperm with an elongated straight head about 1 µm in diameter, head+middlepiece 12 µm long, acrosome 1.5 µm, nucleus 6 µm, middlepiece 4.5 µm, and flagellum 45 µm long. Females deposited eggs about 100 µm in diameter into capsules which were joined to each other in a string and attached to the inner wall of the burrow by two stalks. Larvae developed inside the capsules until the 3 -chaetiger stage, when they hatched and continued development in the water column until the 16–18 -chaetiger stage, feeding on the plankton. Morphology of the capsules and early, encapsulated larvae resembled those of P. ecuadoriana. Larval development of the species will be described elsewhere. Remarks Worms identified herein as P. cf. haswelli resemble P. ecuadoriana in many characteristic features. The two species occur together in shells, have similarly variable pigmentation on palps and anterior chaetigers, an incised prostomium, caruncle extending posteriorly to the end of chaetiger 3, spermatids joined in tetrads, similar dimensions of oocytes and spermatozoa, and morphology of early larvae. The extreme forms of each species can easily be distinguished by the shape of pygidium: those referred to P. ecuadoriana have a large, scoop-shaped pygidium, while P. cf. haswelli individuals have a small, disc-like to cup-shaped pygidium. However, the morphology of the pygidium is variable in both species, including form intermediate between the cup- and scoop-shaped pygidia (Fig. 9 B). Other characteristics that might be diagnostic, such as the dentition of chaetiger 5 falcate spines (single lateral flange versus lateral tooth and small subterminal flange), and the presence of small yellow chromatophores on the posterior segments, are also variable, making delineation of the species ambiguous. Lateral additional structures on old falcate spines (situated in the anterior part of the row) were worn and indistinct, while on new spines (situated in the posterior part of the row) they appeared as one complete large flange or lateral tooth and small subterminal flange, depending on the view of observation and quality of the preparation. Yellow chromatophores were absent in some live worms with all the other characteristics corresponding to P. cf. haswelli. This variability raised a problem of conspecificity of worms with large, scoop-shaped and small, disc-like pygidia (see below doubts about identification as P. haswelli). Pelagic Polydora larvae caught in a creek entering Espírito Santo Bay in the state of Espírito Santo provided support for the idea of two sympatric species. Two kinds of larvae were found in the plankton and only P. ecuadoriana and P. cf. haswelli were present on the bottom, boring in oyster shells. The larvae appeared very similar in most diagnostic characteristics but differed unambiguously in the shape and position of melanophores on the lateral peristomial lips. It is plausible that two Polydora species co-occur in the area and they are able to interbreed on occasion, resulting in individuals with intermediate shape of the pygidium. Further molecular investigations are certainly needed to clarify this issue. Meanwhile worms with scoop-shaped and disc-like pygidia are distinguished taxonomically. Another problem to solve was the identification of the two species under discussion. The diagnostic features and taxonomic status of P. ecuadoriana are discussed above in this paper, while reasoning for P. cf. haswelli is provided here. Although both species demonstrate variable pigmentation (even absent in some individuals), they can be referred to a group of Polydora species having characteristic black bars on palps. Those species were reviewed by Williams & Radashevsky (1999: Table 1) and Radashevsky & Hsieh (2000: Table 1) but the Brazilian worms fit none of them. Both reviews, however, overlooked P. ecuadoriana and P. haswelli. The original description of the latter species referred ambiguously to “additional pigment on palps” (Blake & Kudenov 1978: p. 259) but James A. Blake clarified that "pigment spots occurred along the palps" (e-mail of 3 November 2003 to VIR). This clarification made P. neocaeca Williams & Radashevsky, 1999 (originally described from Rhode Island, U.S.A.) and P. haswelli Blake & Kudenov, 1978 (originally described from New South Wales, Australia) similar to each other and raised a problem of their identity. Both species are shell-borers with almost identical main characteristic features, including body and palp pigmentation and the shape of the pygidium. They differ in the shape of additional structures on major falcate spines of chaetiger 5, with large accessory tooth and smaller vertical flange above the tooth present in P. haswelli (Blake & Kudenov, 1978: fig. 44 C–E), and an obliquely curved flange present in P. neocaeca (Williams & Radashevsky 1999: fig. 1 D). These differences are not, however, unambiguous and should be studied more carefully since both kinds of spine lateral structures may vary. Sperm morphology might be informative for the species delineation and is used herein for a tentative identification of the Brazilian worms. Polydora neocaeca has spermatids joined in octads (Williams 2000) and spermatozoa with acrosome 0.9 ± 0.1 µm, nucleus 4.8 ± 0.4 µm, middlepiece 4.2 ± 0.4 µm (Williams & Radashevsky 1999; Williams 2000). Polydora cf. haswelli collected in Brazil have spermatids joined in tetrads, and the spermatozoa differ in measurements from those of P. neocaeca. The number of spermatids joined together by cytoplasmic bridges is species specific, 4 or 8 in examined Polydora species, and has been used for distinguishing between sibling species (Radashevsky & Pankova 2006). Information about spermatid aggregation and sperm morphology of P. haswelli from Australia is lacking. Pending more details on morphology of the Australian material, we refer to the Brazilian specimens as P. cf. haswelli. Remarkably, P. h a s w e l l i has not been reported outside of Australia, and P. ecuadoriana was recorded only from Ecuador. Further molecular investigations would clarify the identification of the Brazilian worms referred to these species. Distribution Australia: New South Wales; Brazil: Espírito Santo south to Santa Catarina.Published as part of Radashevsky, Vasily I., Lana, Paulo C. & Nalesso, Rosebel C., 2006, Morphology and biology of Polydora species (Polychaeta: Spionidae) boring into oyster shells in South America, with the description of a new species, pp. 1-37 in Zootaxa 1353 on pages 17-22, DOI: 10.5281/zenodo.17453

Oyster spat recruitment in Espírito Santo State, Brazil, using recycled materials

This paper evaluated the effectiveness of four types of oyster spat collectors, made with recycled materials, in the recruitment of the mangrove oyster Crassostrea spp. at five sites in the Benevente river estuary, Anchieta District and on two islands in Piúma District, both in Espírito Santo State. The collectors were made of: 1- oyster shells, 2- PET bottles, 3- car tires and 4- tiles, all of them suspended by ropes and tied to roots of Rhizophora mangle or mussel long-lines. The number of spat recruited on each collector and their shell lengths were registered bimonthly, as well as the physico-chemical-trophic parameters of the water: salinity, temperature, dissolved oxygen, particulate organic matter and chlorophyll a, which were correlated (by Spearman's correlation) with the number of spat recruited. Spat settlement was significantly higher on oyster shell, tile and tire collectors, mainly at points with higher salinities, such as Praia do Coqueiro in Anchieta and on Meio and Cabrito Islands in Piúma (Kruskal-Wallis: H= 10.01; 3 d.f.; p < 0.05). Oyster spat recruitment occurred throughout the year, being higher from November to February, but because of losses due to storms or theft, the difference was not statistically significant (Kruskal-Wallis: H=1.42; 7 d.f.; p > 0.05). The number of oyster spat was positively correlated with the salinity (&#961;s= 0.331; p < 0.05) and water temperature (&#961;s= 0.48; p < 0.05), revealing that areas with higher salinities and summer months were better for spat collection