A new species of the genus Acyrtus on the eastern Pacific: A cornerstone for the evolution and biogeography of the genus.

The genus Acyrtus Schultz, 1944 currently includes four species distributed in the western Atlantic (WA), three occurring from the Bahamas to the southern Caribbean, and one endemic to the Fernando de Noronha Archipelago in north-east Brazil. We describe a new species of Acyrtus based on morphology and genetics from several individuals caught at artificial hard substrates deployed between 10 and 16 m deep at Malpelo Island, Colombian Pacific. The Malpelo clingfish, Acyrtus arturo new species, differs from all its WA congeners by a combination of morphology, meristics and genetics. This species is unique within Acyrtus in having the greatest number of caudal rays (12-13). It can also be distinguished by the greater body height (19.8-27.8% standard length), its longer disc (34.0-39.1% standard length) and the greater distance between anus and disc (13.9-18.1% standard length). A. arturo sp. nov. is the first Acyrtus so far recorded from the eastern Pacific and adds to the already high number of fishes endemic to Colombia's remote oceanic territory of Malpelo.

The masquerade game: marine mimicry adaptation between egg-cowries and octocorals.

Background. Background matching, as a camouflage strategy, is one of the most outstanding examples of adaptation, where little error or mismatch means high vulnerability to predation. It is assumed that the interplay of natural selection and adaptation are the main evolutionary forces shaping the great diversity of phenotypes observed in mimicry; however, there may be other significant processes that intervene in the development of mimicry such as phenotypic plasticity. Based on observations of background mismatching during reproduction events of egg-cowries, sea snails of the family Ovulidae that mimic the octocoral where they inhabit, we wondered if they match the host species diversity. Using observations in the field and molecular systematics, we set out to establish whether the different egg-cowrie color/shape polymorphisms correspond to distinct lineages restricted to specific octocoral species. Methods. Collection and observations of egg-cowries and their octocoral hosts were done using SCUBA diving between 2009 and 2012 at two localities in the Tropical Eastern Pacific (TEP), Malpelo Island and Cabo Corrientes (Colombia). Detailed host preference observations were done bi-annually at Malpelo Island. We analyzed the DNA sequence of the mitochondrial genes COIand 16S rDNA, extensively used in phylogenetic and DNA barcoding studies, to assess the evolutionary relationship among different egg-cowrie colorations and morphologies. Results. No genetic divergence among egg-cowries associated to different species of the same octocoral genus was observed based on the two mitochondrial genes analyzed. For instance, all egg-cowrie individuals from the two sampled localities observed on 8 different Pacifigorgia-Eugorgia species showed negligible mitochondrial divergence yet large morphologic divergence, which suggests that morphologies belonging to at least two sea snail species, Simnia avena(=S. aequalis) and Simnialena rufa, can cross-fertilize. Discussion. Our study system comprised background-matching mimicry, of the masquerade type, between egg-cowries (Simnia/Simnialena) and octocorals (Pacifigorgia/Eugorgia/Leptogorgia). We observed mimicry mismatches related to fitness trade-offs, such as reproductive aggregations vs. vulnerability against predators. Despite the general assumption that coevolution of mimicry involves speciation, egg-cowries with different hosts and colorations comprise the same lineages. Consequently, we infer that there would be significant tradeoffs between mimicry and the pursuit of reproductive aggregations in egg-cowries. The findings of this study not only contribute to the understanding of the evolution of mimicry in egg-cowries, a poorly studied group of marine gastropods, but also to the development of a new biologically meaningful board game that could be implemented as a learning tool.

Conservation Genetics of the Scalloped Hammerhead Shark in the Pacific Coast of Colombia.

Previous investigations of the population genetics of the scalloped hammerhead sharks (Sphyrna lewini) in the Eastern Tropical Pacific have lacked information about nursery areas. Such areas are key to promoting conservation initiatives that can protect young sharks from threats such as overfishing. Here, we investigated the genetic diversity, phylogeography, and connectivity of S. lewini found in 3 areas of Colombia's Pacific coast: around Malpelo Island and in 2 National Natural Parks on the Colombian Pacific mainland (Sanquianga and Ensenada de Utría). We analyzed mtDNA control region (CR) sequences and genotyped 15 microsatellite loci in 137 samples of adults and juveniles. The mtDNA analyses showed haplotypes shared between the Colombian Pacific individuals sampled in this investigation and other areas in the Eastern Tropical Pacific, the Indo-Pacific, and with sequences previously reported in Colombia (Buenaventura Port), as well as 4 unique haplotypes. Population assignment and paternity analyses detected 3 parent-offspring pairs between Malpelo and Sanquianga and 1 between Malpelo and Utría. These results indicate high genetic connectivity between Malpelo Island and the Colombian Pacific coast, suggesting that these 2 areas are nurseries for S. lewini. This is, to our knowledge, the first evidence of nursery areas identified for the scalloped hammerhead shark anywhere in the world. Additional conservation planning may be required to protect these nursery habitats of this endangered shark species.

Flora terrestre de la isla Malpelo (Colombia), Pacífico Oriental Tropical / Terrestrial flora of Malpelo Island, Colombia, Eastern Tropical Pacific

Malpelo Island is located 380km off the mainland continental coast of Colombia, in the Pacific Ocean. Several geological, ecological, and zoological studies, both marine and terrestrial, have been conducted in this island. Despite some marginal comments on some publications, no single specific survey has been devoted to botany so far. In order to make a floristic inventory of the terrestrial flora of this island, three field trips were made in 2010 to collect vascular plants, mosses, and lichens, as well as data on their distribution within the island. We collected and identified 25 species of lichens, two species of vascular plants and one moss. Lichens were the most diverse group found, including records of four new genera (Endocarpon, Fuscidea, Lecanographa and Verrucaria) and 13 new species for Colombia. The high lichen richness on Malpelo might be explained by their efficient form of asexual reproduction (soredia and isidia), that may have facilitated their transport to the island by migrating birds or wind. Once on the island, it is possible that lichens persist by being chemically protected against herbivores. The great number of new generic and species records for Colombia is explained by the low number of studies in saxicolous lichens conducted so far in the country, particularly on coastal areas and remote islands. Only two species of vascular plants were collected, a grass, Paspalum sp., and a fern, Pityrogramma calomelanos, and both of them correspond to new determinations for Malpelo. A moss species previously reported but with no positive identification was collected and identified as Octoblepharum albidum. Other species previously reported, for example, some species of shrubs, were not observed. The low number of vascular plants is probably due to a combination of soil conditions and herbivory by land crabs. This study is the first complete inventory of the flora of Malpelo and is a starting and reference point for future comparisons among islands in the Eastern Tropical Pacific. Rev. Biol. Trop. 62 (1): 327-336. Epub 2014 March 01.

La isla Malpelo se encuentra en el Pacífico colombiano, a unos 380km de la costa continental. La Isla ha sido objeto de algunos estudios geológicos, ecológicos y faunísticos, tanto marinos como terrestres, pero ningún estudio estrictamente botánico. Con el fin de realizar un inventario de la flora terrestre de Malpelo, se realizaron tres salidas de campo durante el 2010, en las que se recolectaron plantas vasculares, musgos y líquenes, y se tomaron datos sobre su distribución en la Isla. El grupo más diverso correspondió a los líquenes, con 25 especies, incluidos cuatro nuevos géneros para Colombia, Endocarpon, Fuscidea, Lecanographa y Verrucaria, y 15 nuevos registros de especies para Colombia. La alta riqueza de especies de líquenes en la Isla puede deberse a la forma de reproducción asexual de estos organismos, que pudieron haber sido transportados hasta Malpelo por aves migratorias o por viento; además, pueden estar protegidos químicamente de la herbivoría por cangrejos terrestres. La gran cantidad de registros nuevos para Colombia se explica por la poca cantidad de trabajos en líquenes saxícolas en el país, sobre todo en zonas costeras e insulares. Solo se registraron dos especies de plantas vasculares, una gramínea, Paspalum sp., y un helecho, Pityrogramma calomelanos. También se recolectó una especie de musgo, Octoblepharum albidum. La escasez de plantas vasculares probablemente se deba a la combinación de condiciones de los suelos y a la herbivoría por cangrejos terrestres. El presente estudio es el primero en darle relevancia a la flora terrestre de Malpelo y constituye un punto de referencia y comparación para estudios semejantes en otras islas del Pacífico Oriental Tropical.

First record and impact of the crown-of-thorns starfish, Acanthaster planci (Spinulosida: Acanthasteridae) on corals of Malpelo Island, Colombian Pacific

The crown-of-thorns starfish, Acanthaster planci, is a major coral predator widely distributed in the Indo-Pacific region, where population outbreaks have caused dramatic impacts on coral reefs. In the Tropical Eastern Pacific (TEP) A. planci occurs at low population densities; it has been significantly abundant only in Panama and Cocos Island. We have recently found two individuals of A. planci at Malpelo Island, a small oceanic island with significant coral communities located off the Colombian Pacific coast. The recent discovery of A. planci at Malpelo is significant in light of recent reports of its increased frequency of observation at Cocos Island and occurrence at the Galapagos Islands. The individuals found at Malpelo have been repeatedly sighted since 2004, actively feeding on nine species of coral. Although densities of A. planci are low at Malpelo and other oceanic islands of the TEP, these islands may act as stepping stones for the colonization of other coral reef areas in the region. However, the low densities of A. planci suggest that it currently poses no threat to coral reefs in the TEP. Rev. Biol. Trop. 58 (Suppl. 1): 139-143. Epub 2010 May 01.

La estrella de mar corona de espinas Acanthaster planci, es un importante depredador de coral ampliamente distribuido en la región del Indo-Pacifico, donde explosiones poblacionales han causado dramáticos impactos sobre los arrecifes coralinos. En el Pacifico Oriental Tropical (POT) A. planci ocurre con densidades poblacionales bajas; solamente en Panamá e Isla de Cocos su abundancia ha sido significativa. Nosotros encontramos recientemente al menos dos individuos de A. planci en la Isla de Malpelo, una pequeña isla oceánica con comunidades coralinas importantes localizada en el Pacífico Colombiano. El hallazgo de A. planci en Malpelo es significativo a la luz de reportes recientes de un incremento en su frecuencia de observación en Isla de Cocos y su registro en Galápagos. Los individuos encontrados en Malpelo han sido repetidamente observados alimentándose activamente de nueve especies de coral desde 2004. Aunque las densidades de A. planci son bajas en Malpelo y otras islas oceánicas del POT, éstas pueden actuar como trampolín de dispersión para la colonización de otras áreas arrecifales en la región. Sin embargo, las bajas densidades de A. planci sugieren que actualmente ella no representa amenaza alguna para los arrecifes del POT.