The presence of populations of the Western Indian Ocean coelacanth (Latimeria chalumnae) in Madagascar is not surprising considering the vast range of habitats which the ancient island offers. The discovery of a substantial population of coelacanths through handline fishing on the steep volcanic slopes of Comoros archipelago initially provided an important source of museum specimens and was the main focus of coelacanth research for almost 40 years. The advent of deep-set gillnets, or jarifa, for catching sharks, driven by the demand for shark fins and oil from China in the mid- to late 1980s, resulted in an explosion of coelacanth captures in Madagascar and other countries in the Western Indian Ocean. We review coelacanth catches in Madagascar and present evidence for the existence of one or more populations of L. chalumnae distributed along about 1000 km of the southern and western coasts of the island. We also hypothesise that coelacanths are likely to occur around the whole continental margin of Madagascar, making it the epicentre of coelacanth distribution in the Western Indian Ocean and the likely progenitor of the younger Comoros coelacanth population. Finally, we discuss the importance and vulnerability of the population of coelacanths inhabiting the submarine slopes of the Onilahy canyon in southwest Madagascar and make recommendations for further research and conservation.SIGNIFICANCE: • The paper contributes significantly to knowledge of the distribution and ecology of the Indian Ocean coelacanth, Latimeria chalumnae. • The paper provides the first comprehensive account of Madagascar coelacanths and demonstrates the existence of a regionally important population and extensive suitable habitat, correcting an earlier hypothesis that coelacanths in southwest Madagascar were strays from the Comoros. • The results have application in the study of the evolution, biology, ecology and conservation of the species. • The significant threat posed by gillnet fishing to coelacanths and other species is highlighted as are the negative effects of the shark-fin trade. • The paper emphasises the importance of the Onilahy marine canyon in southwest Madagascar as an especially important habitat and provides the basis for the development of a national programme of research and conservation.

ABSTRACT We report on the pioneering discovery of Devonian fish remains in the Paraná Basin, which represents the southernmost record of fishes from that period in mainland South America. The material comes from an outcrop at the lower portion of the São Domingos Formation, within Sequence C of the Paraná-Apucarana sub-basin in Tibagi, State of Paraná. Marine invertebrates are abundant in the same strata. The dark colored fish remains were collected in situ and represent natural moulds of partially articulated shark fin rays (radials). No elements such as teeth or prismatic cartilage have been preserved with the fins rays. This can be attributed to the dissolution of calcium-phosphatic minerals at the early stages of fossilization due to diagenetic processes possibly linked to strong negative taphonomic bias. This may have contributed to the fact that fishes remained elusive in the Devonian strata of this basin, despite substantial geological work done in the Paraná State in recent decades. In addition, the scarcity of fish fossils may be explained by the fact that the Devonian rock deposits in this basin originated in a vertebrate impoverished, cold marine environment of the Malvinokaffric Realm, as previously suspected.

El objetivo de este estudio es reportar un evento de necrofagia que involucra el consumo de un tiburón nodriza (Ginglymostoma cirratum) por tiburones tigre (Galeocerdo cuvier) en el archipiélago de Fernando de Noronha, Brazil. Buzos aficionados encontraron y fotografiaron los restos mordidos de un tiburón nodriza, justo después de ver a dos tiburones tigre cerca del lugar. Mediante el análisis forense de imágenes estimamos la longitud total de los tiburones, y discutimos aspectos de esta interacción alimenticia. Una cortada recta en la aleta caudal del tiburón nodriza, cuya longitud total se estimó en 200 cm, sugiere que fue objeto de pesca ilegal. El desprendimiento de la piel observado en las aletas del tiburón nodriza indica que los tiburones tigre lo consumieron después de su muerte, en un evento de necrofagia. Este es el primer reporte publicado de un evento de necrofagia que involucra el consumo de un elasmobranquio por tiburones tigre, lo cual permite una mejor comprensión de su biología alimentaria.

The aim of this study is to report a scavenging event, involving the consumption of a nurse shark, Ginglymostoma cirratum, by tiger sharks, Galeocerdo cuvier, at Fernando de Noronha archipelago, Brazil. Recreational divers found and photographed a bitten nurse shark carcass, just after sighting two tiger sharks near of the site. We estimated the sharks total lengths and discussed aspects of this feeding interaction using of images of forensic analysis. A straight cut on the nurse shark caudal fin, whose total length was estimated as 200 cm, suggest that it was caught by illegal fishing. A skin peeling process on the nurse shark fins indicates that the tiger sharks consumed it after its death, in a scavenging event. This is the first published report of a scavenging event involving the consumption of an elasmobranch by tiger sharks, allowing a better comprehension of tiger sharks' alimentary biology.

O objetivo deste estudo é relatar um evento de necrofagia, envolvendo o consumo de um tubarão lixa, Ginglymostoma cirratum, por tubarões tigres, Galeocerdo cuvier, no arquipélago de Fernando de Noronha, Brasil. Mergulhadores recreativos encontraram e fotografaram uma carcaca de tubarão lixa com marcas de mordida, logo após avistarem dois tubarões tigres no mesmo local. A análise forense das imagens permitiu estimar o comprimento total dos tubarões, bem como discutir aspectos desta interacão alimentar. Um corte reto na nadadeira caudal do tubarão lixa, cujo comprimento total foi estimado em 200 cm, sugere que ele foi vítima da pesca ilegal. A descamacão das nadadeiras indica que o tubarão lixa foi consumido pelos tubarões tigres depois de morto, em um evento de necrofagia. Este é o primeiro reporte publicado de necrofagia de um elasmobránquio por tubarões tigres, contribuindo para a compreensão de sua biologia alimentar.

A new species of shark belonging to the family Ginglymostomatidae is herein described; the new species show a wide distribution in the Tropical Eastern Pacific, where it is endemic. Ginglymostoma unamisp. nov. was previously recognized as G. cirratumexhibiting an amphi-American distribution; however that species is now considered to be restricted to the Atlantic Ocean. Ginglymostoma unamisp. nov. can be readily distinguished from G. cirratumby comparing several meristic characters such as the distance between the prebanchial and interdorsal regions, and that between posterior end of the second dorsal fin and the beginning of the caudal lobe, both being shorter; the new species also differs by the position of the insertion of the first dorsal fin with regard to the pelvic fins and in the form and number of keels on the dermal denticles and teeth morphology.

Se describe una especie nueva de tiburón perteneciente a la familia Ginglymostomatidae; la distribución de esta especie es amplia en el Pacífico oriental tropical (POT), donde es endémica. Ginglymostoma unamisp. nov. se describe a partir de ejemplares procedentes del POT identificados bajo el nombre de Ginglymostoma cirratum, especie que se consideraba con distribución anfiamericana; esta última ahora se restringe al océano Atlántico. Ginglymostoma unamisp. nov. se distingue de G. cirratumpor una serie de caracteres morfométricos, tales como la distancia entre la región prebranquial y la interdorsal, aquella entre el extremo posterior de la segunda aleta dorsal y el inicio del lóbulo caudal superior, que son más cortas y, por último, por la distancia entre la axila y el inicio de la aleta anal; también difiere por la posición de la inserción de la primer aleta dorsal con respecto a aquella de las pélvicas y en la forma y número de quillas en los dentículos dérmicos y morfología dental.

Accurate species identification is one of the most important issues to conserve and manage shark fisheries. A multidisciplinary approach involving molecular (using variation at ITS2 sequences), morphometrical and image processing species identification was performed to evaluate their discriminating power with three pelagic shark species common to the coasts of Chile (Prionace glauca Linnaeus 1785, Isurus oxyrinchus Rafinesque 1810, and Lamna nasus (Bonnaterre, 1788). Species-specific DNA markers and multivariate analyses based on twenty morphometrical measurements were used to identify fresh and dry fin sets for each shark species. Additionally, coloring patterns and fin shape were jointly used to distinguish dry fin sets of shark species by using digital invariant correlation (relation target and problem image independent of their changes in position, scale and rotation). Our results showed that morphometrical analysis was the least accurate approach, whereas DNA-based identification and image processing approaches were 100% successful on the identification of shark species. Thus ITS2 sequences and morphological diagnostic characteristics such as the ones related to color patterns, allow the correct identification of shark species. Therefore, the implementation of molecular and/or image tools can be applied to confidently identify the main pelagic shark species involved in Chilean landing and fin trade.

La identificación correcta de las especies es uno de los más importantes temas para la conservación y el manejo de las pesquerías de tiburones. Un análisis multidisciplinario que involucra el procesamiento de datos moleculares, morfométricos e imágenes fue realizado para evaluar su capacidad de discriminación de tres especies de tiburones pelágicos comunes en las costas de Chile (Prionace glauca Linnaeus 1758, Isurus oxyrinchus Rafinesque 1810, and Lamna nasus Bonnaterre, 1788). Marcadores moleculares especie-específicos y análisis multivariados basados en 20 mediciones morfométricas, fueron usados para identificar grupos de aletas húmedas y secas de cada especie de tiburón. Adicionalmente, patrones de coloración y forma de la aleta fueron usados conjuntamente para distinguir grupos de aletas secas de las especies de tiburones utilizando correlación digital invariante (relación entre la imagen conocida y la imagen problema, independiente de sus cambios de posición, escala y rotación). Nuestros resultados muestran que el análisis morfométrico es el enfoque menos exacto, mientras que la identificación basada en el ADN y el procesamiento de imágenes fue 100% exitosa para reconocer las especies de tiburones en cuestión. Así, secuencias del ITS2 y caracteres diagnósticos en la morfología, tales como aquellos relacionados al patrón de coloración, permiten la identificación correcta de las especies de tiburones. Por lo tanto, la implementación de herramientas moleculares y/o de imagen permiten confidentemente identificar a las principales especies de tiburones pelágicos involucrados en el desembarque y comercio de aletas en Chile.

The lack of species-specific landing records has produced difficulties in shark stock assessments in Chile. Given that the records are insufficient for fisheries assessments, it is imperative to have trustable morphological characteristics for the identification of species or parts of their bodies (such as fins). This study describes morphological characters useful for the identification of fins of the three main traded pelagic shark species (P. glauca, I. oxyrhinchus andL. nasus). Results showed that there are diagnostic morphological characters to identify the fins of these three species. Given that the studied species are the most traded ones, the descriptions of the fins and the taxonomic keys per fin type developed in this study should be of high use to monitor landings of shark, especially fins in sacs. The knowledge of the proportion of traded species and the quantity of each is important for future fisheries assessments and the establishment of management plans.

La carencia de registros de desembarque especie-específicos ha producido dificultades en la evaluación de stock de tiburones en Chile. Debido a que los registros son insuficientes para realizar evaluaciones pesqueras, es imperativo contar con características fidedignas para la identificación de las especies o partes de éstas (como las aletas). El presente estudio describe caracteres morfológicos para la identificación de las aletas de las tres especies más importantes de tiburones pelágicos comercializados en Chile (P glauca, I. oxyrhinchusyL. nasus) y provee de claves dicotómicas para la identificación de estas especies usando ya sea la aleta pectoral, la primera dorsal o la caudal. Los resultados revelaron que existen caracteres diagnósticos para identificar las aletas de cada una de estas especies. Ya que las especies estudiadas son las que más se comercializan, las descripciones de las aletas y las claves taxonómicas por tipo de aleta desarrolladas en este estudio prometen ser de gran utilidad para los fiscalizadores, en particular aquellos que se enfrenten a los desembarques de sacos de aletas. Además, el poder conocer tanto la cantidad como la proporción de especies comercializadas, es importante para futuras evaluaciones pesqueras y el establecimiento de planes de manejo especie-específicos.

En "El Faro del fin del mundo", los autores relatan sus experiencias e impresiones frente al viaje a la Isla de los Estados, en la punta sur de Argentina. Más adelante, en "Los Balcanes y las alucinaciones de la literatura", Ford reflexiona sobre el conflicto que viven aquellos que se dedican a las letras entre el imaginario histórico, cultural y literario, y la cruda realidad contemporánea, usando como base un viaje a los Balcanes y el texto de La Canción de Rolando. Ya en "Haroldo y las aletas de tiburón" Ford narra cómo Haroldo Conti, escritor argentino asesinado por el régimen militar, quiso hacerse rico vendiendo aletas de tiburón a los japoneses, por lo que recorre múltiples balnearios de su provincia; no obstante, a causa de la extensión del viaje y las vicisitudes de la marcha, abandona el proyecto y se dedica a disfrutar los placeres del viaje.

In "El faro del fin del mundo", the authors narrate their trip to the Isla de los Estados, south to Argentina, and their related experiences. Then, in "Los Balcanes y las alucinaciones de la literatura" Ford reflects on the conflict writers have between historical, cultural and literary imaginaries, and contemporary reality; all by means of the story of a trip to the Balkans and the Canción de Rolando. Finally, in "Haroldo y las aletas de tiburón", the author narrates how Haroldo Conti—Argentinean writer murdered by the military regime—wanted to become rich by selling shark fins to the Japanese, thus, he travels across multiple beaches of his province. Nonetheless, because of the extension of the trip and his multiple adventures, he abandons the idea and simply enjoys the pleasuresof traveling.

Un total de 80 especímenes de Pandarus satyrus, un copépodo ectoparásito cosmopolita, fueron tomados de tiburones azules (Prionace glauca) capturados en la costa del Pacífico Oriental de Costa Rica. Todos los especímenes fueron encontrados en la superficie dorsal de las aletas pectorales (entre 8 y 30 por tiburón). Los parásitos más grandes son los más abundantes.

A total of 80 specimens of Pandarus satyrus, a cosmopolitan ectoparasitic copepod, were taken from fishery catches of blue sharks (Prionace glauca) in the Eastern Pacific coast of Costa Rica. All specimens were found in the dorsal surface of pectoral fins (8-30 per shark). Longer specimens were most abundant.

Noventa e um espécimes jovens e 3 fêmeas adultas de "cação cabeça chata" capturados na região lagunar de Cananeia foram examinados, constatando-se a fórmula dental 27/25 e número de vértebras pré-caudais entre 109 e 115.Verificouse que as proporções entre a la. nadadeira dorsal e a 2a. foram de 2.3 e 2.8 para os jovens e de 2.9 até 3.1 para os adultos.Ficou assim confirmado que a forma es tudada pertence a C. leuaas. É comum a ocorrência de jovens dentro da região estudada~ no entanto,quanto aos adultos,as fêmeas só são encontradas durante o período de parição, i.é, de novembro a fevereiro. Constatou-se que o número de embriões nas ninhadas foi de 7 a 9 e seus tamanhos oscilaram ent re 768-812 mm. O comprimento do menor jovem livre encontrado foi de 697 mm, sendo que jovens de presumivelmente 9 a 12 meses têm de 98 a 112 cm; entre 21 e 24 meses alcançam 124 a 128 cm, ou seja, os tamanhos que apresentam quando emigram para mar aberto. Não ficou confirmado o fenômeno da inibição alimentar nas fêmeas capturadas, já observado em genetrizes da mesma espécie durante o período de parição no delta do Mississippi. O conteúdo estomacal apresentou, por ordem decrescente de abundância: Arius spixii (13); Chloroscombrus chrysurus (7); A. grandicassus (6); A. barbus (4); Felichtys marinus (3); Genidens genide ns (2); Chanophorus tajacica (2); Carcharhinus porosus (2); Conodon nobilis, Caranx crysos, scomberomorus maculatus, Sphyrna tiburo, Rhinoptera brasiliensis, Dasyatis americana, Diapterus rhombeus (1), além de cerca de 25/30 exemplares de Callinectes sp.

Ninety one young specimens and 3 adult females of BulI shark ("cação cabeça chata") caught in the lagoon region of Cananéia were examined, their tooth formula being 27/25 and the number of pre-caudal vertebrae ranging from 109 to 115. The proportion between the 1st and 2nd dorsal fins were found to be 2.3 and 2.8 for the young,and 2.9 to 3.1 for the adults. These data confirm that the studied form belongs to C. leuoas. Young occur regularly but in limited numbers.As regards the adults, however, females only appear during the short parturition period, i.e., from November to February. The number of embryos in the litters were from 7 to 9, their sizes ranging between 768-812 mm. The length of the smallest free young found was 697 mm, but young presumably 9 to 12 months old had 98 to 112 cm; between 21 and 24 months they were reaching 124 to 128 cm, that is, the same size they have when they start migrating to the open sea. The feeding inhibition phenomenon during the period of parturition was not observed in the female specimens caught in the lagoon. The more abundant species found in the stomach contents were: Arius spixii; Chloroscombrus chrysurus; A. grandicassus; A. barbus; Felichtys marinus; Genidens genidens; Chanophorus tajacica and Carcharhinus porosus.