Claudia Bremec

• Senior Researcher at National Scientific and Technical Research Council

Ancient and modern marine environments are usually characterized by colonizers associated with living and dead organisms, as well as inorganic substrates. There are different terminologies to characterize these colonizations, i.e., if the roots of the terms refer to the colonizer or the colonized substrate. The terminology stated by Paul D. Taylor...

El Área Marina Protegida Namuncurá/ banco Burdwood fue creada en el año 2013 y fue la primera región protegida off-shore de la Argentina. Acompañando al Proyecto de Ley, se encontraba un informe técnico liderado por Falabella V. en el que se aportó, entre otras cosas, información sobre taxones bentónicos previamente registrados en el área (entre el...

Introduction: The first open-sea (non-coastal) Marine Protected Area in Argentina, named “Namuncurá I” (NMPA), was created in 2013 at Burdwood Bank (BB), an undersea plateau located about 200 km south from Malvinas Islands (Falkland Islands) and 150 km east from Staten Island, SW Atlantic Ocean. It comprises three different management areas: the ce...

Prey selection and feeding strategy of the Argentine hake Merluccius hubbsi were investigated by analyzing the diet and prey availability in the main nursery area of the Patagonian stock (42.4°-46.4 °S, 70-102 m depth). Stomach contents from fish captured using a bottom trawl net, and zooplankton samples collected with a Bongo net, were analyzed. A...

This work describes the composition and distribution of sclerobionts on the Miocene Patagonian oyster Ostrea alvarezii d'Orbigny and provides information about its paleoenvironment. The structure of sclerobiont assemblages and their preferential distribution on left/right valves (n=340) as well as their external/internal surfaces and areas was eval...

El presente capítulo resume el estado de arte sobre epibiosis y bioerosión en el Mar Argentino a partir de las contribuciones producidas por los integrantes del Laboratorio de Bentos del INIDEP. En particular, se abordan los aspectos teóricos y los antecedentes sobre el asentamiento y desarrollo de comunidades epibiontes, el rol de los principales...

En este capítulo se presentan de manera sinóptica los trabajos bentónicos submareales desarrollados en las diferentes regiones del Río de la Plata y zonas marinas adyacentes por el Laboratorio de Bentos del INIDEP a partir de mediados de los años ‘90. Se espera de esta manera lograr una mejor comprensión ecosistémica de las comunidades bentónicas d...

Los fondos duros proveen un número importante de hábitats para distintas asociaciones de peces e invertebrados bentónicos, convirtiéndose de esta manera en zonas de alto interés tanto por su importancia pesquera como para la conservación de la biodiversidad marina. En este capítulo se presenta información sobre los estudios llevados a cabo en el La...

SUMMARY Damage estimate in benthic invertebrates discarded in the Patagonian scallop fishery. The catch of Patagonian scallop fishery Zygochlamys patagonica are mechanically processed onboard. Non-target species and non-commercial size scallops are separated by metal drums and discarded. The aim of the present study was to analyze the direct damage...

A well-replicated decadal-term (2005–2014) stomach content data set was analysed in order to infer inter-annual fluctuations in the diet of the Argentine hake, Merluccius hubbsi, an opportunistic predator in the San Jorge Gulf (SJG) ecosystem in the Southwest Atlantic. Ten research cruises were carried out each year during January from 2005 to 2014...

We investigated the fouling community on the Fisheries Vessel (F/V) Khronometer during a 3‐year period, from its sinking, by means of video transects. The results demonstrate that the shipwreck presented high macroinvertebrate coverage from the first survey (100 days after sinking). The most conspicuous organisms were cnidarians, followed by amphip...

This study reports the identity of foraminiferans within rosetted borings assigned to Semidendrina pulchra (Bromley, Wisshak, Glaub, Botquelenon, 2007) on the Recent oyster Ostrea puelchana d'Orbigny, 1842, from San Matías Gulf (Patagonia, Argentina). Foraminiferan tests were removed from their bioerosion traces and, SEM (Scanning Electron Microsco...

The diet and trophic level (TL ) of the yellownose skate Zearaja chilensis in the south-western Atlantic Ocean (35°-54° S), and how these varied in relation to body size, sex, maturity stage, depth and region were determined by analysis of stomach contents. From 776 specimens analysed, 671 (86·5%) ranging from 180 to 1190 mm total length (LT ) had...

This study compared the composition and frequency of encrusting, boring and vagile organisms or ‘sclerobionts’ on two patagonian oysters: Ostrea puelchana d’orbigny (Recent) and Ostrea alvarezii d’orbigny (Miocene). The structure of sclerobiontic assemblages and its preferential recruitment on left/right valves and their xternal/internal surfaces w...

Biological data were collected in a Patagonian scallop fishing ground, between 39°00' and 39°50' S and between 87 and 130 m depth. During 2007, we sampled the following stations where the trawling exerted could be precisely determined: 11 locations subjected to continuous fishing effort between 1996 and 2006 (continuous fishing effort, 878 commerci...

The present paper reports the occurrence of the Antarctic coral Flabellum impensum in Tierra del Fuego Province, Argentina, and extends its distribution northwards in the south-west Atlantic Ocean. Nine individuals were found in Argentinean coastal waters in 2014, also representing one of the shallowest records of the species.

The aim of this study was to compile and analyse available historical information on echinoderms in the southwestern Atlantic Ocean in order to make a synthesis of present taxonomical knowledge, to identify patterns of geographical distribution of echinoderm assemblages and to test the validity of the current zoogeographic scheme for this group. Th...

The diet and the trophic level of the Argentine hake Merluccius hubbsi was investigated on the Southwest Atlantic Ocean. Stomachs from 3405 specimens, ranging from 10 to 94 cm total length, collected on three research cruises carried out during winter 2011 and summer 2012, were examined at the laboratory. Dietary shifts related to sex, maturity sta...

The continental slope of the southern SW Atlantic Ocean has many distinguishable deep submarine canyons, varying in depth and extension. The benthic fauna within one of them, detected in April 2005 by means of a multibeam SIMRAD EM1002 sonar, and located at 43°35′S to 59°33′W, 325 m depth, was studied to discuss faunal affinities with the neighbour...

The present study provides a quantitative and qualitative analysis on the dentition of Mustelus schmitti, and estimates the tooth-replacement rate. In total, 47 males and 56 females of M. schmitti were collected on scientific trawl surveys conducted by the National Institute of Fisheries Research and Development (INIDEP) in Argentina during the mon...

The presence of the oyster Pycnodonte (Phygraea) vesicularis (Lamarck) is recorded in the Maastrichtian mudstones of the Jaguel Formation. This species was free-lying and inhabited muddy bottoms in a shallow marine shelf with a low sedimentation rate. Their shells supported a diverse community including fungi, algae, sponges, cirripedes, bryozoans,...

The spatial and temporal patterns within the surf zone epibenthic assemblages were studied in a coastal fringe of Argentina to determine whether assemblage compositions, abundance, species richness and diversity vary spatially and temporarily. Sampling was conducted seasonally in two sandy beaches over 2 years with a benthic sledge used to collect...

El presente capítulo compila aspectos generales de Rapana venosa (Neogastropoda, Muricidae), así como información relativa a enfoques ecológicos y socio-económicos sobre el mencionado caracol invasor desarrollados recientemente en el Río de la Plata y zonas costeras adyacentes. Igualmente se identifican actores, herramientas y medidas de control y/...

Ophiuroidea represents the dominant invertebrate group in Patagonian scallop fishery by-catch in the south-western Atlantic. This study presents information that brings forward the spatial patterns and abundance of the most abundant species in the benthic community associated with this fishery at the shelf-break front in the Argentine Sea, between...

Byssate bivalves can be attached to hard substrates by byssal threads. Dissolution of the substrate to which they are attached may leave superficial bioerosion traces. This study reports the scars produced by byssus of Mytilus edulis and Aulacomya atra recorded in shells of Ostrea puelchana. Oyster valves were cut and gold-sputtered prior to scanni...

Ostrea puelchana d'Orbigny, 1842 is a common species of commercial interest in Patagonia and is distributed from Rio Grande do Sul (Brazil) to San Matías Gulf(SMG, Argentina). In SMG, the species develops natural banks that provide irregular surfaces suitable for colonization of organisms. We studied the composition and frequency of encrusting and...

This contribution reports the first record of intertidal reefs built by the sabellariid worm Sabellaria nanella in the lower intertidal at Monte Hermoso beach, Argentina (39°S). All previous records of S. nanella in the study area correspond to solitary individuals from shallow subtidal depths in coastal environments, while the present findings ref...

The composition of endobionts in the sponge Mycale (Aegogropila) magellanica at the shelf-break, near 100m depth, in the Argentine Sea was studied. We also provide new information on the distribution of M. (A.) magellanica, extending its northern limit to 38º36.02’S and 55º44.68’W, 91 m in the SW Atlantic Ocean. The main Patagonian scallop fishing...

An inventory of 24 fish species incidentally caught by the Patagonian scallop fleet in the SW Atlantic Ocean is provided for the first time. The most frequent species were Psammobatis spp. (81.4%), Bathyraja brachyurops (75.1%), B. macloviana (73.5%), Patagonotothen ramsayi (66.1%), Merluccius hubbsi (53.7%) and B. albomaculata (50.3%). Many of the...

Aequipecten tehuelchus (d'Orbigny, 1846) is a commercial resource, distributed from Rio de Janeiro (Brazil) to Golfo Nuevo (Argentina), on sandy and muddy bottoms. In Argentina, the major banks of exploitation are located in the gulfs of San José and San Matías. This study represents the first ecological study of A. tehuelchus in shelf waters off B...

Patagonian scallop scientific name. Considering the present taxonomic options, it is proposed to continue using the scientific name Zygochlamys patagonica for the commercial species commonly known as "Patagonian scallop". RESUMEN Considerando las opciones taxonómicas actuales, se propone continuar utilizando el nombre científico Zygochlamys patagon...

SUMMARY. The pacific oyster Crassostrea gigas (Thunberg 1793) in Buenos Aires: natural recruitments in Samborombón bay. The Pacific oyster Crassostrea gigas is one of the most successful invasive species worldwide, inhabiting intertidal and shallow subtidal marine and mixohaline coastal waters. In Argentina the species colonized natural ecosystems...

In the present study we identified a total of 26 sponge taxa, to be added to the 4 sponge species previously registered, living epizoically on Fusitriton magellanicus shells, an abundant and frequent gastropod in the shelf-break frontal area of the Argentine Sea, SW Atlantic Ocean. The majority of the recorded sponges were encrusting living specime...

In this study, a Picard dredge was used to sample the benthic community in shelf break frontal areas off Argentina in order to detect species that could be sensitive to fishing activities but are not usually caught during the annual monitoring of Patagonian scallop and associated fauna. The present results show at least 62 taxa not reported previou...

This study describes the macrofaunal assemblages of subtidal rocky reefs off Mar del Plata in order to compare the macro invertebrate assemblages settled on shipwrecks with those of nearby reef sand to characterize the fish fauna associated with natural (NR) and artificial (AR) reefs. Topographic characterizations and surveys of invertebrates and f...

This study describes the macrofaunal assemblages of subtidal rocky reefs off Mar del Plata in order to compare the macro invertebrate assemblages settled on shipwrecks with those of nearby reef sand to characterize the fish fauna associated with natural (NR) and artificial (AR) reefs. Topographic characterizations and surveys of invertebrates and f...

The feeding ecology of Mustelus schmitti was studied based on analysis of stomach contents of 525 specimens collected from three research cruises carried out during October 2008 to March 2009 on the Argentinean continental shelf (34º45′S–41ºS). Generalized Linear Models were used to test the effects of Geographic location, Total Length, Sex and Mat...

Ctenodiscus australis is a common sea star in the Argentine Continental Shelf. Nevertheless, information about its population parameters is lacking. We investigated the spatial distribution, biomass and size structure of this sea star through a spatial and temporal scale in Patagonian scallop (Zygochlamys patagonica) fishing grounds associated with...

In this study we describe the feeding biology of the exotic predatory whelk Rapana venosa from the Rıó de la Plata when offered representative coastal bivalves from both soft and hard bottoms. Furthermore, we estimate daily consumption rates using two mussel species commonly found on local rocky outcrops and artificial reefs. R. venosa gastropods (...

An inventory of the main epibiont organisms on living specimens, on empty shells and on pagurized shells of Fusitriton magellanicus collected in Zygochlamys patagonica fishing grounds off Argentina is provided here. Additionally, considering that the presence of the thick, hairy periostracum could be an inhibitor of boring and encrusting species, w...

RESUMO Alimentação da corvina Micropogonias furnieri (Sciaenidae; Pisces) no estuário do Rio da Prata e águas costeiras do Uruguai Estudamos a dieta da corvina (Micropogonias furnieri) (Pisces) em distintos regimes de salinidade e tipos de fundo no estuário do Rio da Prata e nas águas costeiras adjacentes do Uruguai. Analisamos 258 conteúdos estoma...

We used a comprehensive dataset on the diet of Squalus acanthias in the southwestern Atlantic Ocean (35–55°S) to test the hypothesis that fishery has caused a decrease in the trophic level of this species (fishing down process). Of 3,644 stomachs examined between the years 1985 and 2010, 2,214 (60.77%) contained prey items. Generalized linear model...

An inventory of the main epibiont organisms on living specimens, on empty shells and on pagurized shells of Fusitriton magel-lanicus collected in Zygochlamys patagonica fishing grounds off Argentina is provided here. Additionally, considering that the presence of the thick, hairy periostracum could be an inhibitor of boring and encrusting species,...

In this study, a Picard dredge was used to sample the benthic community in shelf break frontal areas off Argentina in order to detect species that could be sensitive to fishing activities but are not usually caught during the annual monitoring of Patagonian scallop and associated fauna. The present results show at least 62 taxa not reported previou...

The present paper reports the occurrence of Polyonyx gibbesi in Argentinean shelf waters and extends its distribution southwards in the western Atlantic. Forty-four specimens of P. gibbesi were found in stomach contents of the narrownose smoothhound shark Mustelus schmitti during November 2008.

In the current study we provide information to aid in the identification of bivalve larvae in plankton samples based on the descriptions of recently settled spat of Zygochlamys patagonica and Hiatella meridionalis, 2 conspicuous bivalves commonly distributed in the shelf-break frontal system of the Argentine Sea. The first species is of particular...

The aim of this paper is to study the polychaete composition from a wide area in the Argentinean shelf, between 36°S and 55°S, by means of samples collected from soft bottoms with Picard dredge, during the "Shinkai Maru" cruises developed in 1978-79. As the study area comprises both the Magellanic and Argentinean Biogeographic Provinces, we analyze...

Desde el inicio de la pesquería de vieira patagónica, Zygochlamys patagonica, en el Mar Argentino, en 1996, el Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) estableció un Programa de Observadores a Bordo (OBOP). Se analizaron las tendencias generales en la composición de la captura incidental a partir de información provista po...

Since the beginning of the Patagonian scallop fishery Zygochlamys patagonica, in the Argentine Sea in 1996, an On-Board Observers Program (OBOP) was established at the National Institute of Fishery Research and Development (INIDEP). The general trends of the bycatch composition and biomass were analysed from information on catches and fishing effor...

This paper provides updated taxonomic knowledge about hydrozoan species and provides ecological information including geographical and bathymetric distributions and biological substrata for the various hydroid assemblages from the Sub-Antarctic Biogeographical Region, mainly Buenos Aires and the Uruguayan coasts. Five of the 41 species found are ne...

Flexopecten felipponei (Dall, 1922) is a non-commercial, seldom reported pectinid from the SW Atlantic Ocean. In this contribution we review its taxonomy, describe epifaunal species and their levels of encrustation, and discuss the composition of the macrobenthic assemblage where this scallop lives. Eighteen epibiont taxa were observed to live on t...

The Patagonian scallop (Zygochlamys patagonica) fishery started in the Argentine Sea after exploratory cruises developed during 1995. Knowledge concerning the habitat requirements involved in the settlement processes of the target species was lacking. The main objectives of this study are to find Z. patagonica spat and to assess the characteristics...

In this study we compare the composition, structure and biomass of the species assemblage in the Patagonian scallop management unit “Reclutas” (39°00′–39°30′S and 55°45′–56°05′W), in areas subjected to fishing effort (FG) and in the exclusion area (REX), between 1998 and 2002. Data obtained during 1995 and previous to the beginning of the scallop f...

The present paper analyzes the diet, feeding strategy and niche width of Bathyraja albomaculata over the Patagonian continental shelf and upper slope. The diet comprised a variety of 14 small invertebrates, although the most important prey were polychaete worms. The opheliid polychaete Travisia sp. and the gammarid amphipod Cirolana sp. were the ma...

The present paper analyses the diet, feeding strategy and niche width of B. macloviana in a sector of the Argentinean Continental Shelf (ACS). Individuals (n = 147) were collected from 43 sampling stations in late summer and autumn 2001. Thirty one alimentary items in the gut contents were found, with a clear dominance of polychaetes. Crustaceans w...

In this study we present results on epibionts on Zygochlamys patagonica from material collected during monitoring cruises in different areas in the Argentine Sea. We update the checklist of epibionts increasing the number of taxa from 19 to 41 and considering two species closely associated with the shells. The demosponge Iophon proximum was the mos...

We present an overview of repaired shell damage in the scallop Zygochlamys patagonica in the commercial beds of the Argentine Sea. Presence of scars was registered in 11962 scallops, ranging from 20 to 90 mm total height, from the fishing grounds in 2003 and also in 1995 (pre-fishery condition). Values of percentage of scarring (presence) were vari...

La presente revisión reúne la información disponible sobre comunidades de invertebrados bentónicos del Mar Argentino y brinda un perfil histórico del desarrollo de esta línea de investigación en el país.Se incluyen los antecedentes bibliográficos locales y una breve caracterización faunística de acuerdo con la distribución latitudinal,la profundida...

In this study, we analyse spatial patterns of macrobenthic communities of the Río de la Plata system, and assess the species turnover or beta diversity and its relationship with environmental gradients. Macrobenthic samples and physico-chemical parameters were collected from 20 sampling sites along a transect of 560 km, including the freshwater (FW...

Since the beginning of the Patagonian scallop fishery in 1996 (Res. ex-SAGPyA N°150/96), an Observers On Board Program (INIDEP) was established. Observers are technically qualified persons that collect important information about fishing practices, that are essential to promote sustainable fisheries management and fishing activity. Observers are pr...

We studied the diet of the whitemouth croaker (Micropogonias furnieri) (Pisces) in the Río de la Plata estuary and adjacent Uruguayan coastal waters. Fish were caught at different salinity ranges and bottom types. We analyzed 258 gut contents of whitemouth croaker (6-67 cm total length, TL) and calculated an index of relative importance of prey (IA...

This chapter discusses the two species, Aequipecten tehuelchus (Tehuelche scallop) and Zygochlamys patagonica (Patagonic scallop), their fisheries, and experimental results that have significance in the future development of aquaculture. The fisheries supported by these two species are radically different from each other. The Tehuelche scallop is t...

Porifera are a frequently collected taxon in the invertebrate by‐catch of the Patagonian scallop Zygochlamys patagonica (King & Broderip 1832) fishery. In order to prevent the destruction of the exploited environments in the Argentine Sea, it is important to know in detail the taxonomic composition of the benthic assemblages. We present here the fi...

Polychaete assemblages were studied from samples taken in the Southwestern Atlantic, between 34°S and 38°S (Argentinean. Biogeographical Province) during 1993, 2001 and 2002 from a series of oceanographic cruises in mixohaline to oceanic waters. Polychaetes represented almost 25% (number of taxa) of the macrobenthic assemblages; 57 taxa correspondi...

Recent range extensions of the invasive rapa whelk Rapana venosa, biological data of the population and possible ecological impacts on the food webs of the Río de la Plata estuary are presented. A total of 41 rapa whelks and 21 egg capsules were collected between February 2004 and March 2006. Specimens were found all over the mixohaline waters of t...

In this work, we evaluated the food web structure associated with a Patagonian scallop Zygochlamys patagonica fishing bed using stable isotopes as an indirect technique. Scallops showed δ13C isotope signatures between −17.9‰ and −18.8‰ in muscle and −20.9‰ and −22.6‰ in gonads, which may indicate additional fractionation during metabolic transfers...

Considering that the analysis of total gut contents in large sized bivalve species is extremely time-consuming, the aim of the present study is to give a statistically tested methodology that permits quantitative assessment of gut contents in bivalves from selected subsamples. Thirty Patagonian scallops Zygochlamys patagonica (35–55 mm total height...

The present paper analyses the diet, feeding strategy and niche width of B. macloviana in a sector of the Argentinean Continental Shelf (ACS). Individuals (n = 147) were collected from 43 sampling stations in late summer and autumn 2001. Thirty one alimentary items in the gut contents were found, with a clear dominance of polychaetes. Crustaceans w...

Parandalia tricuspis (Müller 1858) y Sigambra cf. tentaculata (Treadwell 1941) fueron registrados en áreas submareales frente a Mar del Plata (38°S, 57°W, Argentina). Ésta constituye la primera mención de P. tricuspis en aguas argentinas. El género Sigambra era conocido para la región patagónica; la presente cita extiende hacia el norte su distribu...

Sabellaria bellis Hansen, 1882 y S. wilsoni Lana & Gruet, 1989 fueron registradas en diversos habitats costeros de Uruguay y Argentina, entre 34°S y 37°S, Provincia Biogeográfica Argentina. Se discuten los patrones de distribución local en relación con la hidrografía. Nuestros resultados indican que ambas especies son tolerantes a los cambios de sa...

This study deals with the spatial distribution of macrobenthic communities (biomass and abundance) in the Rı́o de la Plata estuary, Argentina–Uruguay, and the adjacent shelf waters. The benthic invertebrates were caught with an epibenthic dredge (41 samples). Multivariate analysis (cluster, MDS), SIMPER and BIO-ENV analyses were applied to analyze...

Sabellaria bellis Hansen, 1882 and S. wilsoni Lana & Gruet, 1989 were recorded in different habitats from coastal localities of Uruguay and Argentina, between 34°S and 37°S, Argentinean Biogeographic Province. Local distribution patterns in relation with the hydrography are discussed. Our findings show that both species are tolerant to salinity cha...

Commercial catches of Patagonian scallops (Zygochlamys patagonica) are automatically processed on board the fishing vessel and frozen adductor muscles are landed. During the factory process, the first step sorts commercial sizes (>55 turn shell height) and lasts about 30 min before scallops <55 mm are returned to the sea. This paper deals with the...

The presence of persistent fish assemblage areas in estuaries can result from spatially structured environmental gradients, which determine a pattern of biological zonation. In the Rı́o de la Plata estuary (36 °S, 56 °W), those assemblage areas were defined for summer, autumn, and spring of 1996. Cluster analysis identified groups of sampling stati...

Opheliid polychaetes belonging to the genera Armandia, Ophelia, Ophelina, and Travisia, collected along the Southwestern Atlantic coast off Brazil and Argentina, are recorded or given extended descriptions. Travisia amadoi sp. n., Ophelina gaucha sp. n. and Ophelina alata sp. n. are described.

The present paper reports the occurrence of Ebalia rotundata (A. Milne-Edwards, 1880) in marine waters off Argentina and Uruguay, and thus extends its known geographical distribution in the Argentinean Zoogeographical Province more than 700 km northwards. Feasible dispersal mechanisms of this species are discussed. Este trabajo reporta la ocurrenci...

This paper provides an overview of the research being carried out at the moment by a group of Argentinean scientists working on the subjects of marine biodiversity and oceanography. When the idea of the Census of Marine Life (CoML) was proposed following the Symposium held during the IAPSO-IABO conference in Mar del Plata in October 2001, there was...

A series of surveys on shallow shelf bottoms along the southwestern Atlantic coast were conducted to determine the composition and distribution of benthic communities, and their response to sewage discharge and pollution. Polychaetes of the family Opheliidae were identified as belonging to the genus Armandia, which is herein newly reported from Arg...

INIDEP, the National Institute for Fisheries Research Pesquero (INIDEP) es un organismo descentralizado del and Development, is a decentralized state agency created Estado, creado según Ley 21.673, sobre la base del ex Insti-by Statute Law 21,673, on the basis of the former tuto de Biología Marina (IBM). Tiene por finalidad la for-Institute of Mari...

This article deals with the diet of the Patagonian scallop, Zygochlamys patagonica, during a yearly period at Reclutas bed (39ºS – 55ºW), Argentine Sea, and relates the results with the oceanographic conditions and the growth pattern known for this species. Scallops (n=180) from six samples were dissected and gut contents were identified and counte...

Cannibalism by fishes on planktonic eggs is typical of filter-feeding marine planktivores, i.e. fishes that have the ability for filtering large volumes of water and concentrate small food particles. We report an unusual case of cannibalism on planktonic eggs by adults of the non-filter feeding fish Micropogonias furnieri, which are opportunistic b...