Spatial variation of parrotfish assemblages at oceanic islands in the western Caribbean: evidence of indirect effects of fishing?

Fish populations that bear considerable pressure levels tend to show a decline in the average size of individuals, with the small and unexploited species replacing the large and exploited ones. It is important to carry on with their characterization in areas where they are becoming an important source of food for local human populations. An example of such species are parrotfishes, whose responses to external factors such as fishing need to be understood and predicted. In this study, we used a diver-operated stereo-video to examine individual body size, sex ratios and proportion of species of the parrotfish assemblage and analyze them on a qualitative fishing pressure gradient at four oceanic islands in the Colombian Caribbean. We reported over 10,000 occurrences of eleven parrotfish species, of which we estimated the total length of over 90%, grouping them into three size categories (large, medium, and small). Our data showed a spatial variation of parrotfishes' abundances, biomass, and individual body size. Observed differences are size-category-dependent throughout the qualitative fishing pressure. In general, the medium-bodied species had smaller sizes, lower abundances, and thus lower contribution to the total parrotfish biomass at the most heavily fished island. Unexpectedly, we found evidence of possible indirect effects over the small-bodied species Scarus iseri and Scarus taeniopterus with significantly greater abundances, and larger sizes of males of S. iseri, at the higher fishing pressure sites. Overall, our data highlights the extent of the spatial variation in the parrotfish communities at relatively short distances, and present new insights into the responses of parrotfish species on a spectrum of body sizes along a gradient of human pressure.

A new species of deep-sea grunt, Rhonciscus pauco (Lutjaniformes: Haemulidae), from Puerto Rico.

A fourth species of the genus Rhonciscus (Lutjaniformes: Haemulidae) is described from various specimens collected by small-scale fishers from the insular upper slope of western Puerto Rico. The new species was molecularly recovered as sister to the Eastern Pacific R. branickii, to which it bears many morphological similarities. It is distinguished from other Rhonciscus species by the number of scale rows between the dorsal fin and the lateral line (7), larger and thus fewer scales along the lateral line (48-50), large eyes (9.4-10.4 times in SL), longer caudal peduncle (15.2-20% of SL), larger sized penultimate (14.7-19.1% in SL) and last (7.4-9.5% in SL) dorsal fin spines which translates to a less deeply notched dorsal fin, and its opalescent silver with golden specks live coloration. This grunt, only now recognized by ichthyologists, but well known by local fishers that target snappers and groupers between 200 and 500 m in depth, occurs in far deeper waters than any western Atlantic grunt.

Evolutionary determinism and convergence associated with water-column transitions in marine fishes.

Repeatable, convergent outcomes are prima facie evidence for determinism in evolutionary processes. Among fishes, well-known examples include microevolutionary habitat transitions into the water column, where freshwater populations (e.g., sticklebacks, cichlids, and whitefishes) recurrently diverge toward slender-bodied pelagic forms and deep-bodied benthic forms. However, the consequences of such processes at deeper macroevolutionary scales in the marine environment are less clear. We applied a phylogenomics-based integrative, comparative approach to test hypotheses about the scope and strength of convergence in a marine fish clade with a worldwide distribution (snappers and fusiliers, family Lutjanidae) featuring multiple water-column transitions over the past 45 million years. We collected genome-wide exon data for 110 (∼80%) species in the group and aggregated data layers for body shape, habitat occupancy, geographic distribution, and paleontological and geological information. We also implemented approaches using genomic subsets to account for phylogenetic uncertainty in comparative analyses. Our results show independent incursions into the water column by ancestral benthic lineages in all major oceanic basins. These evolutionary transitions are persistently associated with convergent phenotypes, where deep-bodied benthic forms with truncate caudal fins repeatedly evolve into slender midwater species with furcate caudal fins. Lineage diversification and transition dynamics vary asymmetrically between habitats, with benthic lineages diversifying faster and colonizing midwater habitats more often than the reverse. Convergent ecological and functional phenotypes along the benthic-pelagic axis are pervasive among different lineages and across vastly different evolutionary scales, achieving predictable high-fitness solutions for similar environmental challenges, ultimately demonstrating strong determinism in fish body-shape evolution.

NOTAS SOBRE LA REPRODUCCIÓN, MORFOLOGÍA Y ECOLOGÍA DE Pareques acuminatus (TELEOSTEI: SCIAENIDAE), EN LA REGIÓN DE SANTA MARTA, CARIBE COLOMBIANO / Notes on the reproduction, morphology and ecology of Pareques acuminatus (Teleostei: Sciaenidae), in the region of Santa Marta, Colombian Caribbean

RESUMEN Pareques acuminatus (familia Sciaenidae) es una especie carnívora de tamaño pequeño, que se distribuye en el Atlántico occidental entre Carolina del Norte y Bermudas hasta Brasil. Los estudios sobre la biología y ecología de P. acuminatus son escasos y en Colombia no se han realizados trabajos concernientes a la especie. El propósito de este estudio fue conocer aspectos de reproducción, morfología y ecología con el fin de ampliar su conocimiento en el Caribe colombiano. Entre 2017 y 2018 se realizaron capturas en cinco localidades por medio de buceo libre y se realizaron censos visuales del hábitat donde fue observada. Se evaluó la morfometría y merística, se identificaron las fases reproductivas y se estimó la fecundidad parcial mediante el método gravimétrico. Un total de 85 individuos fueron recolectados con una LT entre 33 y 185 mm (123,7±36,3 mm) siendo más frecuentes aquellos entre 121-142 mm (42 %) seguidos de los de 143-164 mm (20 %). Se distinguieron 39 hembras, 34 machos y 12 juveniles indeterminados debido a su pequeño tamaño. La talla de las hembras maduras fue a partir de una LT de 118 mm, siendo una especie asincrónica con dos fases reproductivas (en desarrollo y con capacidad de desove). La fecundidad parcial estimada fue de 8744 ± 3900 oocitos y la fecundidad relativa con relación a la talla fue de 64,15 ± 25,51 oocitos/mm, con un diámetro de 0,53 ± 0,04 mm. Pareques acuminatus es una especie típica de hábitats arrecifales someros y se encontró en conjunto con Myripristis jacobus, Canthigaster rostrata, Haemulon steindachneri, H. flavolineatum, Stegastes partitus y Chromis multilineata, que fueron las especies comunes en todas las localidades.

ABSTRACT The highhat, Pareques acuminatus, is a carnivorous, small sized species, with distribution in the western Atlantic from North Carolina and Bermuda to Brazil. Studies on the biology and ecology of P. acuminatus are scarce and in Colombia no work has been done concerning this specie. For this reason, this study focused on knowing the biology of this sciaenid and determining ecological aspects in order to expand its knowledge in the Colombian Caribbean. Captures of the highhat were made by free diving between 2017 and 2018 and visual fish censuses were taken on the habitat where it was observed between 2017 and 2018. The morphometrics and meristics were taken, the reproductive phases identified, and the partial fecundity estimated by the gravimetric method. A total of 85 individuals were collected with a TL between 33 and 185 mm (123.7 ± 36.3 mm) with individuals between 121-142 mm (42 %) as the more frequent, followed by 143-164 mm (20 %). There were 39 females, 34 males and 12 indeterminate juvenile specimens. Females reach mature state with 118 mm TL, being an asynchronous species, with two reproductive phases (phase in development and phase capable of spawning). The estimated partial fecundity was 8744 ± 3900 oocytes, and the relative fecundity in relation to size was 64.15 ± 25.51 oocitos/mm with a diameter of 0.53 ± 0.04 mm. The highhat is a typical specie of shallow reef habitats, and was found mainly accompanied by Myripristis jacobus, Canthigaster rostrata, Haemulon steindachneri, H. flavolineatum, Stegastes partitus and Chromis multilineata between 2017 and 2018.

Multilocus phylogeny, divergence times, and a major role for the benthic-to-pelagic axis in the diversification of grunts (Haemulidae).

We present a phylogenetic analysis with divergence time estimates, and an ecomorphological assessment of the role of the benthic-to-pelagic axis of diversification in the history of haemulid fishes. Phylogenetic analyses were performed on 97 grunt species based on sequence data collected from seven loci. Divergence time estimation indicates that Haemulidae originated during the mid Eocene (54.7-42.3 Ma) but that the major lineages were formed during the mid-Oligocene 30-25 Ma. We propose a new classification that reflects the phylogenetic history of grunts. Overall the pattern of morphological and functional diversification in grunts appears to be strongly linked with feeding ecology. Feeding traits and the first principal component of body shape strongly separate species that feed in benthic and pelagic habitats. The benthic-to-pelagic axis has been the major axis of ecomorphological diversification in this important group of tropical shoreline fishes, with about 13 transitions between feeding habitats that have had major consequences for head and body morphology.

Megalops atlanticus (Megalopidae), a new fish at the Pacific Ocean; information about its fishery importance / Megalops atlanticus (Megalopidae), un nuevo pez en el océano Pacífico; información sobre su importancia pesquera

ABSTRACT Objective . Reports by the first time Megalops atlanticus, commonly known as tarpon, from the Colombian Pacific Ocean, discussing its distribution, uses, and value for local human populations. Material and methods . Interviews with fishermen from the municipalities of Nuquí and Bahía Solano (Chocó Province) were carried upon in order to collect information about fishing points, ecologic characteristics, and uses of tarpon; samples were additionally taken in order to determine sex, gonadal maturity, and stomach contents. Results. Fifty interviews were made to fishermen who declared have fished tarpon at least once; fishing methods (hook and line, spear, and gill net) and main uses [consumption (65%), handcraft production (20%), commerce (7%) and game fishing (8%)] were got from them. Conclusions. Our study should be the base for additional research and management strategies for this species both in the Pacific and Caribbean Colombian coasts.

RESUMEN Objetivo. Registrar la presencia de Megalops atlanticus (sábalo real) por primera vez en el Pacífico colombiano y dar un marco inicial de conocimiento acerca de su distribución, usos y apreciación por parte de las poblaciones locales. Materiales y métodos. Se llevaron a cabo 50 encuestas a pescadores de las comunidades de los municipios de Nuquí y Bahía Solano (departamento del Chocó) con el fin de recabar información acerca de los sitios de captura, características ecológicas y usos; adicionalmente se tomaron muestras donde se determinó sexo y estado de madurez gonadal. Resultados. A partir del conocimiento tradicional de los pescadores se establecieron los métodos de captura (línea de mano, arpón, caña de pescar y trasmallo), sitios de pesca: frente de los centros poblados de Jurubirá, Tribugá, Coquí y Bahía Solano (encontrándose en ambientes rocosos y ensenadas aledañas a estos) y usos que le dan al sábalo: consumo (65%), elaboración de artesanías (20%), venta (7%) y pesca deportiva (8%), adicionalmente en los ejemplares estudiados se evaluó el estado de madurez encontrándose todos en estadio III de maduración. Conclusiones. Este trabajo permite alcanzar un primer marco de conocimiento acerca de la distribución del sábalo en el Pacífico colombiano y su explotación en la región, sirviendo de base para estudios posteriores y planes de manejo que se realicen de esta especie en el Pacífico.

Reef fish community in presence of the lionfish (Pterois volitans) in Santa Marta, Colombian Caribbean / Comunidad de peces arrecifales en presencia del pez león (Pterois volitans) en Santa Marta, Caribe colombiano

Objetive. Fish species community structure and benthic organisms coverage were studied in five localities in Santa Marta where the lionfish is present. Materials and methods. Abundance of fish species, including lion fish, was established using 30 m random visual censuses and video transects; trophic guilds were established according to available references. On the other hand benthic coverage was evaluated using the software Coral Point Count (CPCe) 4.0. Results. Families with higher species numbers were Serranidae, Labridae, and Pomacentridae. Lionfish abundances were low (2.6±2.1 ind/120 m²), but in any case Pterois volitans was observed as the eleventh more abundant species, surpassing species of commercial value such as Cephalopholis cruentata. Species that were found in larger numbers (>100, Thalassoma bifasciatum, Haemulon aurolineatum, Canthigaster rostrata, Abudefduf saxatilis, Chromis cyanea, and Stegastes partitus) were mainly invertebrate eaters, planctivores, and territorial herbivores. Coral coverage showed higher coral percentages in Chengue (69.9%) and Cinto (27.4%), larger sponge percentages in Morro (32.7%); Isla Aguja and Remanso showed the larger figures for abiotic substrate (41.6 and 37%, respectively); corals, sponges, and gorgonians were the components best explaining fish community, but not for the lion fish, which inhabit all studied reef formations. Conclusions. Lion fish is ranked between the 20 more abundant species, with none commercially important species larger, hence no species may qualify as a natural control. Lion fish has as well become a relatively abundant species in Santa Marta reefs, independent of benthic coverage.

Objectivo. Se estudió la estructura de especies de la comunidad íctica y se evaluó la cobertura de organismos bentónicos en cinco localidades en Santa Marta, Colombia con presencia del pez león. Materiales y métodos. Se estimó la abundancia a través de censos visuales y video transectos de 30 m y se estableció el gremio trófico de cada especie según literatura. El sustrato se cuantificó con el software Coral Point Count (CPCe) 4.0. Resultados. Las familias con más especies fueron Serranidae, Labridae y Pomacentridae y, aunque su abundancia promedio fue baja (2.6±2.1 ind/120 m²), Pterois volitans fue la undécima especie más abundante, superando a peces comerciales como Cephalopholis cruentata. Las especies más abundantes fueron invertívoros, planctívoros y herbívoros, tales como Thalassoma bifasciatum, Haemulon aurolineatum, Canthigaster rostrata, Abudefduf saxatilis, Chromis cyanea y Stegastes partitus. Se encontró mayor porcentaje de coral en Chengue (69.9%) y Cinto (27.4%) y de esponjas para Morro (32.7%); para Isla Aguja y Remanso predominó el componente abiótico (41.6 y 37%, respectivamente). Corales, esponjas y gorgonias fueron los componentes que mejor explicaron la comunidad íctica, aunque no para el pez león que habita todas las formaciones arrecifales. Conclusiones. El pez león se ubica entre las 20 especies de peces más abundante, con ninguna especie de importancia comercial en los sitios muestreados que lo supere en talla y que pudiera ser un control natural del invasor. Igualmente, se ha convertido en una especie relativamente abundante en los arrecifes samarios sin importar los atributos del fondo.

ESTRUCTURA DE TALLAS Y PREFERENCIA AL SUSTRATO DEL PEZ LEÓN (Pterois volitans) (SCORPAENIFORMES: SCORPAENIDAE) EN SANTA MARTA (COLOMBIA) / Size Structure and Substrate Preference of the Red Lionfish (Pterois volitans) (Scorpaeniformes: Scorpaenidae) in Santa Marta (Colombia)

El pez león, luego de su invasión al Caribe, fue registrado en el Caribe continental colombiano en 2009, a partir de entonces y para medir su impacto, se han adelantado numerosas estrategias. Este trabajo aporta sobre la estructura de tallas y preferencia al sustrato que se determinó entre diciembre de 2011 y diciembre de 2012 para cinco localidades de Santa Marta, a través de censos visuales en transectos delimitados de 30 x 5 m. Las tallas se agruparon de acuerdo con la distribución de frecuencia en cuatro categorías (uno: entre 8 y 14 cm; dos: entre 15 y 21 cm, tres: entre 22 y 28 cm y cuatro: entre 29 y 35 cm). Se observaron 92 individuos con un promedio de 18,0 ± 5,3 cm. La categoría dos fue la más abundante (n=48) predominando en Morro Grande e Isla Aguja y en junio, julio y agosto. Le siguieron las categorías tres (n=21) y uno (n=20). La categoría cuatro (n=3) fue la menos abundante y se encontró en Morro Grande e Isla Aguja. Las variables que explicaron la correlación entre la abundancia de pez león y el tipo de sustrato fueron la cobertura de esponjas (0,6303) y los corales (0,6111), y los componentes abióticos (-0,9443) (n=50; p<0,001). La abundancia del pez león estuvo marcada por el tipo de estructura en las formaciones arrecifales de cada localidad, sin preferencia por ningún tipo de sustrato, lo que indica una posible adaptación a todo tipo de condición arrecifal.

The lionfish, after its invasion to the Caribbean, was reported in the Colombian continental Caribbean, thereafter and to measure its impact there have been numerous strategies. Size structure and substrate preference were studied for a year between December 2011 and December 2012 in five locations in Santa Marta, through visual censuses in 30x5 m transects. Size were grouped according to the frequency distribution into four categories (one: between 8 and 14 cm, two: between 15 and 21 cm, three: from 22 to 28 cm and four: between 29 and 35 cm). We observed 92 specimens with a mean of 18.0±5.3 cm. Category two, the most abundant (n=48), predominated in Morro Grande and Isla Aguja, from June to August, followed by categories three (n=21) and one (n=20). Category four (n=3) was the less abundant, being found at Morro Grande and Isla Aguja. Variables explaining better the correlation between lionfish densities and type of substrate were sponges (0.6303), coral coverage (0.6111) and abiotic components (-0.9443). Lionfish abundance was marked by the kind of structure available for recruitment; this indicates that the species does not show any substrate preference, adapting to any kind of reef conditions.

Molecular phylogeny of grunts (Teleostei, Haemulidae), with an emphasis on the ecology, evolution, and speciation history of new world species.

BACKGROUND: The fish family Haemulidae is divided in two subfamilies, Haemulinae and Plectorhynchinae (sweetlips), including approximately 17 genera and 145 species. The family has a broad geographic distribution that encompasses contrasting ecological habitats resulting in a unique potential for evolutionary hypotheses testing. In the present work we have examined the phylogenetic relationships of the family using selected representatives of additional Percomorpha based on Bayesian and Maximum likelihood methods by means of three mitochondrial genes. We also developed a phylogenetic hypothesis of the New World species based on five molecular markers (three mitochondrial and two nuclear) as a framework to evaluate the evolutionary history, the ecological diversification and speciation patterns of this group. RESULTS: Mitochondrial genes and different reconstruction methods consistently recovered a monophyletic Haemulidae with the Sillaginidae as its sister clade (although with low support values). Previous studies proposed different relationships that were not recovered in this analysis. We also present a robust molecular phylogeny of Haemulinae based on the combined data of two nuclear and three mitochondrial genes. All topologies support the monophyly of both sub-families (Haemulinae, Plectorhinchinae). The genus Pomadasys was shown to be polyphyletic and Haemulon, Anisotremus, and Plectorhinchus were found to be paraphyletic. Four of seven presumed geminate pairs were indeed found to be sister species, however our data did not support a contemporaneous divergence. Analyses also revealed that differential use of habitat might have played an important role in the speciation dynamics of this group of fishes, in particular among New World species where extensive sample coverage was available. CONCLUSIONS: This study provides a new hypothesis for the sister clade of Hamulidae and a robust phylogeny of the latter. The presence of para- and polyphyletic genera underscores the need for a taxonomic reassessment within the family. A scarce sampling of the Old World Pomadasys species prevents us to definitively point to a New World origin of the sub-familiy Hamulinae, however our data suggest that this is likely to be the case. This study also illustrates how life history habitat influences speciation and evolutionary trajectories.

Phylogenetic and morphologic analyses of a coastal fish reveals a marine biogeographic break of terrestrial origin in the southern Caribbean.

BACKGROUND: Marine allopatric speciation involves interplay between intrinsic organismal properties and extrinsic factors. However, the relative contribution of each depends on the taxon under study and its geographic context. Utilizing sea catfishes in the Cathorops mapale species group, this study tests the hypothesis that both reproductive strategies conferring limited dispersal opportunities and an apparent geomorphologic barrier in the Southern Caribbean have promoted speciation in this group from a little studied area of the world. METHODOLOGY/PRINCIPAL FINDINGS: Mitochondrial gene sequences were obtained from representatives of the Cathorops mapale species group across its distributional range from Colombia to Venezuela. Morphometric and meristic analyses were also done to assess morphologic variation. Along a approximately 2000 km transect, two major lineages, Cathorops sp. and C. mapale, were identified by levels of genetic differentiation, phylogenetic reconstructions, and morphological analyses. The lineages are separated by approximately 150 km at the Santa Marta Massif (SMM) in Colombia. The northward displacement of the SMM into the Caribbean in the early Pleistocene altered the geomorphology of the continental margin, ultimately disrupting the natural habitat of C. mapale. The estimated approximately 0.86 my divergence of the lineages from a common ancestor coincides with the timing of the SMM displacement at approximately 0.78 my. MAIN CONCLUSIONS/SIGNIFICANCE: Results presented here support the hypothesis that organismal properties as well as extrinsic factors lead to diversification of the Cathorops mapale group along the northern coast of South America. While a lack of pelagic larval stages and ecological specialization are forces impacting this process, the identification of the SMM as contributing to allopatric speciation in marine organisms adds to the list of recognized barriers in the Caribbean. Comparative examination of additional Southern Caribbean taxa, particularly those with varying life history traits and dispersal capabilities, will determine the extent by which the SMM has influenced marine phylogeography in the region.

Efecto de la herbivoría y coralivoría por peces en la supervivencia de corales trasplantados en el Caribe colombiano

Effect of herbivorous and corallivorous fishes on the survival of transplanted corals in the Colombian Caribbean. To examine the effects of herbivorous and corallivorous fishes on the survival of transplanted colonies of Montastraea annularis, Diploria labyrinthiformis and Porites astreoides, both transplanted and native colonies were full-cage enclosed and compared to open (uncaged) colonies, while caging effects were assessed with a partial-cage (roof treatment). To evaluate if transplant stress increased the corals availability to fish predation, comparisons of fish foraging intensity among transplanted versus native colonies were made. To determine the density of herbivorous and corallivorous fishes on the transplants area visual censuses were made. The transient herbivorous fishes (Scaridae and Acanthuridae) were the most abundant fishes, and the corallivorous fishes (mainly Chaetodontidae) were the scarcest. A negative effect of territorial herbivorous fishes on M. annularis transplants survival was observed, mainly early on the study. Fish foraging intensity was similar on transplanted and native colonies, but differed among coral species, being lowest on D. labyrinthiformis. Fast macroalgal growth inside full-cages due to reduced fish grazing was observed. This caused partial bleaching and partial mortality in some colonies, mainly of P. astreoides. No significant difference in healthy tissue percentages among full-cage and uncaged colonies on M. annularis and D. labyrinthiformis was found, while in P. astreoides there were evident differences. The results indicate a damselfish negative effect on transplants survival early on the study, which can change depending on the fish and coral species involved. Results also indicate a fish grazing positive effect, caused by the reduction of coral-algae competition pressure, mainly on P. astreoides. Parrotfishes seem to affect corals survival both negatively through direct biting, and positively by controlling algal growth. Overall, coral transplant success was almost unaffected by fish foraging activity although several differences among coral species were obvious in relation to colony shape. Additionally, the interaction among herbivorous fish grazing and coral-algae competition balance appear important in determining transplant survival. Rev. Biol. Trop. 55 (3-4): 825-837. Epub 2007 December, 28.

Para investigar el efecto de los peces herbívoros y coralívoros en la supervivencia de colonias trasplantadas de Montastraea annularis, Diploria labyrinthiformis y Porites astreoides se encerraron colonias trasplantadas y nativas en jaulas y se compararon con colonias libres (control), mientras los efectos del encierro fueron evaluados con un tratamiento de techos. Para saber si el estrés debido al trasplante aumentó la vulnerabilidad de los corales a la depredación por peces, se comparó la intensidad de forrajeo por peces entre colonias trasplantadas y nativas. Se realizaron censos visuales para determinar las densidades de las poblaciones de peces herbívoros y coralívoros en la zona de trasplante. Los peces herbívoros móviles (Scaridae y Acanthuridae) fueron los más abundantes, los peces coralívoros (principalmente Chaetodontidae) fueron los más escasos. Se observó un efecto negativo de los peces herbívoros territoriales en la supervivencia de los trasplantes de M. annularis, principalmente al inicio del estudio. La presión de forrajeo fue similar en colonias trasplantadas y nativas, pero fue diferente entre especies, siendo D. labyrinthiformis la menos depredada. En los tratamientos de colonias protegidas en jaulas se observó un crecimiento acelerado de macroalgas debido a la reducción del forrajeo por peces herbívoros. Esto causó blanqueamiento parcial y mortalidad parcial en algunas colonias, principalmente de P. astreoides. En M. annularis y D. labyrinthiformis no se observaron diferencias significativas en los porcentajes de tejido sano de las colonias entre los tratamientos de jaulas y de control, pero sí en P. astreoides. Los resultados sugieren un efecto negativo de los peces herbívoros territoriales en la supervivencia de las colonias durante los primeros días del trasplante; este efecto puede variar dependiendo de las especies de peces y corales involucradas. Los resultados también indican un efecto positivo del forrajeo por peces, debido a la reducción de la presión competitiva alga-coral, sobretodo en P. astreoides. Los scáridos parecen afectar la supervivencia de los corales tanto de manera negativa, al morder en el tejido vivo, como de manera positiva al controlar el crecimiento de las macroalgas. En general, el éxito del transplante de coral fue poco afectado por la actividad de forrajeo de los peces, aunque algunas diferencias entre las especies de coral parecen estar relacionadas con la forma de las colonias. La interacción entre el forrajeo de peces hervíboros y el balance competitivo alga-coral puede ser importante en determinar la supervivencia al transplante.

Systematics and biogeography of New World sea catfishes (Siluriformes: Ariidae) as inferred from mitochondrial, nuclear, and morphological evidence.

Ariid or sea catfishes include around 150 species that inhabit marine, brackish, and freshwater environments along world's tropical and subtropical continental shelves. Phylogenetic relationships for 46 New World and three Old World species of ariids were hypothesized using maximum parsimony and Bayesian inference reconstruction criteria on 2842 mitochondrial (cytochrome b, ATP synthase 8 and 6, ribosomal 12S and 16S) and 978 nuclear (rag2) nucleotide sites. The molecular topologies were compared to a previously compiled morphological dataset that was expanded herein to a total of 25 ariid species and 55 characters. Mitochondrial data yielded clades highly resolved at subfamilial, generic, and intrageneric levels. Nuclear rag2 reconstructions showed poor resolution at supra- and intrageneric levels, but provided support for the monophyly of most genera (except Ariopsis and Cathorops) as well as for the subfamilial clades. The hypothesized phylogeny derived from the morphological data was congruent with the molecular topologies at infrafamilial and generic levels. As indicated by the statistical tests of topological congruence, Kailola's phylogenetic hypothesis of ariids based on anatomical data is significantly different from our molecular trees. All reconstructions agree in the division of the Ariidae into two subfamilies, the Ariinae and the monogeneric Galeichthyinae. Basal ariine resolution was negligible suggesting that early diversification events occurred rapidly. The three Indo-Pacific taxa were grouped into a clade, but New World ariines were never recovered as monophyletic. We provide a revised classification for New World ariines examined, which is consistent with the molecular and the morphological evidence. Our classification scheme includes the genera Ariopsis, Bagre, Cathorops, Notarius, Potamarius, and Sciades, and the description of two new genus-level taxa (Occidentarius n. gen and Precathorops n. subgen.). We also hypothesize plausible biogeographic scenarios that explain distributional patterns of major ariid lineages. Diversification of the predominantly circumtropical ariines likely occurred throughout the Tethys Sea, whereas speciation events in the subtropical galeichthyines were probably tied to the southern coast of Gondwana.