Crossing the borders: First record of Bleeding Wrasse, Polylepion cruentum Gomon, 1977 (Labriformes, Labridae), in the Northern Peru

The Labridae is a species-rich family of colorful fishes distributed globally in different habitats. Polylepion cruentum was described based on type material collected from the Gulf of California, and Quepos, Pacific coast of Costa Rica. It has since been reported from several other localities, including Mexico to Nicaragua and the Cocos Island. Recent collecting efforts in Northern Peru yielded an unusual species of labrid with uncertain taxonomic identity. Measurements, counts, coloration (in life and preserved) and DNA barcoding of the specimen agrees well with Polylepion cruentum. This represents the first record of the species from Northern Peru (Acapulco, Tumbes Department) and South America. The expansion of the distribution range of this species is perhaps due to the input of warm waters to Northern Peru, increasing especially during El Niño events. This new record is important to include in future marine checklists and consequently evaluate the conservation status of this species in Peru.

Rhodolitica on rhodoliths: a new stoloniferan genus (Anthozoa, Octocorallia, Alcyonacea)

Rhodolitica occultagen. nov. et sp. nov. (Clavulariidae) is described from Cocos Island National Park, Pacific Ocean, Costa Rica. The species was found at various islets and rocky outcrops around the island, 20−55 m in depth. The genus is characterised by tubular, single, erect anthosteles interconnected by thin basal ribbon-like stolons on the surfaces of living rhodoliths. The anthosteles are devoid of fused sclerites, which are only present in the stolons. Coenenchymal sclerites are mostly spindles of various shapes, with a characteristic cylindrical warty type in the outer layer, crosses and radiates. Anthocodiae are armed with points, lacking collarets. Colonies and sclerites are red. Using an integrative taxonomic approach, we separate the new genus from similar genera through both morphological comparison and a molecular phylogenetic analysis. This research is a contribution to the knowledge of the octocoral biodiversity in Cocos Island and marine biodiversity in the eastern tropical Pacific.

Ophioderma hendleri sp. nov. (Echinodermata: Ophiuroidea: Ophiodermatidae) and its congeners from the Eastern Pacific

The widespread Ophioderma hendleri sp. nov., from the Eastern Tropical Pacific (Mexico to Colombia) is distinguished from its congeners by having radial shields covered by granules, naked adoral shields, up to 11 arm spines, and by its brown and beige coloration. Ophioderma hendleri sp. nov. belongs to the group of species with naked adoral shields (i.e., O. pentacanthum H.L. Clark, 1917, O. variegatum Lütken, 1856), and it has frequently been misidentified as O. panamense Lütken, 1859 or O. variegatum. Therefore, the main aim of the present work was to describe Ophioderma hendleri sp. nov. and differentiate it from its congeners. The original description of O. panamense was incomplete; thus, we provide a redescription. Due to the confusion in previous designations of its type material, we designate a lectotype and paralectotype of O. variegatum. Finally, we expand the distribution range of O. pentacanthum to Cocos Island, Costa Rica. With this work, the total number of valid species of Ophioderma Müller & Troschel, 1840 in the world increases to 33 and in the Eastern Pacific to nine species.

Thelypteris opulenta (jewelled maiden fern).

Thelypteris opulenta is a perennial fern, native to tropical Asia and Madagascar, that has been introduced as an ornamental to gardens and amenity areas. It produces numerous spores that are easily dispersed by wind and water. It also spreads via rhizomes, stolons and tubers, which are often dispersed to new areas in dumped garden waste. T. opulenta is known to have escaped from cultivation and grows as a weed in disturbed sites, secondary forests and along roadsides and trails. It is listed as a common weed in moist and wet habitats in Central and South America and has been listed as an invasive species in Peru, Costa Rica (Cocos Island) and Cuba.

A brief massive aggregation of pelagic swimming crabs Euphylax dovii (Decapoda: Portunidae) at Cocos Island, Costa Rica coincides with onset of El Niño event

Introduction: Sporadic aggregations of decapod crustaceans can occur for various reasons and in some cases their drivers are poorly understood. Objective: Here, we present our observations of an apparently rare massive aggregation of pelagic swimming crabs, Euphylax dovi. Methods: During a research cruise at Cocos Island (5°32’34” N, 87°05’06” W), we encountered large numbers of E. dovii in surface waters in the evenings of May 6-7, 2015, some of which we collected for identification prior to returning to the water. Results: Crabs of both sexes were identified, yet no females were bearing eggs. Crabs aggregated around a small dinghy used for scientific surveying from 4pm through 8pm each evening, and around our research vessel throughout the night, presumably attracted by the lights. On both occasions, the aggregation dissipated around dawn. Crabs were not seen prior to or after the two nights. Conclusions: Sea surface temperatures at Cocos during this period were markedly warm, with no perceptible thermocline down to at least 40 m, coinciding with the onset of the 2015 El Niño event. It appears that the aggregation formed in response to El Niño conditions, yet the biological reason behind it remains unknown.

Global-to-Cartesian 3-D EM modeling using a nested IE approach with application to long-period responses from island geomagnetic observatories

<p>There is a significant interest in constraining the mantle conductivity beneath oceans. One of the main sources of data that can be used to reveal the conductivity distribution in the oceanic mantle are time-varying magnetic fields measured at island geomagnetic observatories. From these data local electromagnetic (EM) responses are estimated and then inverted in terms of conductivity. The challenge here is that island responses are strongly distorted by the ocean induction effect (OIE) originating from the lateral conductivity contrasts between the conductive ocean and resistive land. OIE is generally modeled by global simulations using relatively coarse grids (down to 0.25 degree resolution) to represent the bathymetry. Insufficiently accurate accounting for the OIE may lead to the wrong interpretation of the observed responses. We study whether the small-scale bathymetry features influence the island responses. To address this question we developed a global-to-Cartesian 3-D EM modeling framework based on a nested integral equation approach, which allows to efficiently account for the effects of high-resolution bathymetry. Two geomagnetic observatories, located in Indian (Cocos Island) and Pacific (Oahu Island) Oceans, are chosen to study the OIE in long-period responses. Numerical tests demonstrate that accounting of the very local bathymetry (down to 1 km resolution) dramatically change modeling results. Remarkably, the anomalous behavior of the imaginary parts of the responses at Cocos Island, namely, the change of sign at short periods, is reproduced by using highly detailed bathymetry.</p>

A review of the records of Pachycheles rugimanus A. Milne-Edwards, 1880 (Crustacea: Decapoda: Anomura: Porcellanidae) from Brazil, with the description of a new species

All previous records of Pachycheles rugimanus A. Milne-Edwards, 1880, from the Brazilian coast are reviewed and prove to represent a new species, P. coelhoi sp. nov. (from Amapá, northern Brazilian coast), and P. ackleianus A. Milne-Edwards, 1880, a species already known from Brazil (from Pará to Rio de Janeiro). The new species is described and illustrated, and compared to its most similar congeners: P. rugimanus and P. ackleianus from the western Atlantic, and P. velerae Haig, 1960, from the eastern Pacific (Galapagos Island and Cocos Island). Pachycheles coelhoi sp. nov. is distinguishable from the other three species by a suite of morphological characters, which include the ornamentation of the carapace and chelipeds, and the shape of the third thoracic sternite. All previous records of P. rugimanus from Brazil are considered invalid.