Dra. Tellier, Florence

Morphological variability is common among macroalgae. In central Chile, Mazzaella laminarioides extends throughout the intertidal rocky zones, where blades are reported to grow up to 20 cm in length. Nevertheless, in low rocky intertidal zones with sand-influence, blades are noticeably larger than in other shores without sand effect. The aim of this study was to compare the morphology of M. laminarioides blades from two different conditions. Blades collected from four sites with, and four without, sand-influence were evaluated with traditional morphometry. Results showed that blades were longer and wider in sand-influenced sites. Sand abrasion was not directly evaluated, but indirect effects such as the abundance of bare rock and of sand tolerant species were higher in areas with sand-influence. Also, long blades were restricted to sand-influenced sites, supporting the relation between these two variables. Molecular analyses using the COI marker confirmed large-bladed individuals as M. laminarioides. Results indicated that life cycle phase, seasonality and vertical height were not related to large blades. We suggest that restriction of large blades to sand-influenced sites may be related to the healing processes of basal holdfasts after suffering sand abrasion.

Siete especies de Rhodymenia han sido registradas para la costa de Perú, donde seis de ellas crecen en la costa central: R. corallina, R. howeana, R. multidigitata, R. flabellifolia, R. skottsbergii y R. californica. La más conflictiva taxonómicamente es R. corallina, de la cual se han segregado R. howeana y R. multidigitata, solo en base a caracteres morfológicos externos (forma del estipe y hábito de la fronda). Recolecciones recientes e intensivas de este complejo de especies en la costa central del Perú (9°S hasta 15°S) han permitido reunir varios morfotipos, evidenciando la alta variabilidad morfológica presente, que dificulta el poder diferenciar cada uno de los taxones involucrados. El objetivo del presente trabajo fue esclarecer la taxonomía de este complejo mediante la combinación de datos morfológicos, tanto vegetativos como reproductivos, y de secuencias genéticas utilizando los marcadores rbcL y COI-5P. Especímenes de Callao, localidad tipo de R. howeana y R. multidigitata, fueron analizados molecularmente junto con material de la costa central (Casma hasta Marcona, 9-15°S) y norte de Perú (Piura, 6°S), así como del norte chico de Chile (Coquimbo, 30°S), resolviendo dos grupos de Rhodymenia: un primer grupo filogenético asociado a R. corallina de Chile (Coquimbo, 30°S), distribuido a lo largo de toda la costa central peruana (Casma hasta Marcona, 9-15°S) y un segundo grupo restringido a la costa norte de Perú (Piura a Casma, 6-9°S). Estos grupos se diferencian en caracteres de la morfología externa y reproductiva. Basado en características del soro tetrasporangial, se reconoce a R. howeana para el norte del Perú.

The intertidal coast of Chile has two cryptic kelp species, Lessonia spicata and L. berteroana, which share closely situated, but not overlapping, high-energy habitats. Their populations recover slowly after major disturbances and massive mortalities, suggesting that dispersal from remnant populations is strongly limited. This low dispersal is also a factor that probably favours the speciation process. Understanding the limiting factors for spore dispersal is crucial. Here we evaluated 1. spore dispersal and spore dilution over distance, 2. if submersion in calm waters for a specific period of time is needed for the settlement of spores before exposure to water movement, and 3. duration of spore attachment ability. Results were consistent with the hypothesis of low-distance dispersal of spores: stained-spore dilution was high at short spatial scales (<4 m); spores settled quickly (1–2 min) even under constant water movement, but they lost the ability to attach rapidly (≤16 h). Water motion did not affect spore attachment to the substratum, a fact probably resulting from an adaptation to high energy intertidal habitats. The very low dispersal range of the spores may explain the strong genetic differentiation at small spatial scales, the speciation event that occurred within the Lessonia species complex and the slow recovery of L. berteroana after massive mortalities occurring with the 1982/1983 El Niño Southern oscillation event.

La sistemática de Bangiales foliosas ha tenido cambios significativos a nivel global, debido a la inclusión de nuevos géneros, como Pyropia, y la incorporación de la evidencia molecular. En Chile, la aplicación de herramientas moleculares ha evidenciado una alta diversidad de especies de los géneros Porphyra y Pyropia, con delimitaciones de especies que no corresponden a las especies definidas con base en caracteres morfológicos. En el Perú, los registros históricos reconocen cincoespecies de Porphyra; sin embargo, su estatus taxonómico aún no ha sido contrastado profundamente con la evidencia molecular. Por ello, este trabajo tuvo como objetivo explorar la diversidad local de las especies de los géneros Porphyra y Pyropia en Marcona, Perú, caracterizando 11 especímenes con los marcadores mitocondrial COI y cloroplastidial rbcL. El análisis filogenético identificó una especie de Porphyra (Porphyra sp. CHF) y tres especies de Pyropia (Pyropia orbicularis, Py. suborbiculata y Pyropia sp. CHI). No hubo coincidencia con los registros históricos de Porphyra. Tres de las cuatro especies encontradas tienen un rango de distribución que comprende Chile y Perú. Este trabajo es un primer avance hacia una caracterización de la diversidad específica del recurso algal conocido en Perú como “cochayuyo”.

Aim: This study examines how rafting on floating bull kelps can shape the biogeographic patterns of raft-associated species, and analyses the spatio-temporal variability of taxonomic richness and co-occurrences of epibionts on beach-cast rafts of Durvillaea antarctica along a latitudinal gradient. Location: Southeast Pacific, along ~1,700 km of coastline. Methods: We examined the epibionts on stranded individuals of D. antarctica on 33 beaches along the continental coast of Chile (28° S–42° S) within four biogeographic districts during the winter and summer of two years (2014/2015–2015/2016). Taxonomic richness and co-occurrences of epibionts within a holdfast were examined. Known geographic ranges and rafting ranges were compared to determine possible range expansions via rafting dispersal. Results: Sessile species were the most frequent epibionts. Taxonomic richness varied among biogeographic zones and seasons, and was higher between 33° S and 42° S than between 28° S and 33° S, particularly in summer compared to winter. Taxonomic richness decreased with floating time (indicated by the presence and size of Lepas spp.). Habitat-forming epibionts such as mytilid mussels, the polychaete Phragmatopoma moerchi and the seaweeds Gelidium lingulatum and Lessonia spicata favoured co-occurrences of other species within a holdfast, suggesting a habitat cascade (i.e. biogenic holdfast—sessile eco-engineers—other epibionts), while the boring isopod Limnoria chilensis and the excavating limpet Scurria scurra were negatively correlated with many other species. Some rafting epibiont species with low dispersal ability were found more than 100–300 km outside of their known geographic ranges, with more extensive ephemeral range extensions at the southern edge of their respective ranges, probably facilitated by higher availability of rafts in those areas. Main Conclusions: These findings confirm that raft-associated species are frequently dispersed outside their known geographic ranges, although these range extensions vary strongly depending on the availability and persistence of rafts, and on the biotic interactions within the rafting assemblage.

Dispersal on floating seaweeds depends on availability, viability, and trajectories of the rafts. In the southern hemisphere, the bull kelp Durvillaea antarctica is one of the most common floating seaweeds, but phylogeographic studies had shown low connectivity between populations from continental Chile, which could be due to limitations in local supply and dispersal of floating kelps. To test this hypothesis, the spatiotemporal dynamics of kelp strandings were examined in four biogeographic districts along the Chilean coast (28°–42°S). We determined the biomass and demography of stranded individuals on 33 beaches for three subsequent years (2013, 2014, 2015) to examine whether rafting is restricted to certain districts and seasons (winter or summer). Stranded kelps were found on all beaches. Most kelps had only one stipe (one individual), although we also frequently found coalesced holdfasts with mature males and females, which would facilitate successful rafting dispersal, gamete release, and reproduction upon arrival. High biomasses of stranded kelps occurred in the northern-central (30°S–33°S) and southernmost districts (37°S–42°S), and lower biomasses in the northernmost (28°S–30°S) and southern-central districts (33°S–37°S). The highest percentages and sizes of epibionts (Lepas spp.), indicative of prolonged floating periods, were found on stranded kelps in the northernmost and southernmost districts. Based on these results, we conclude that rafting dispersal can vary regionally, being more common in the northernmost and southernmost districts, depending on intrinsic (seaweed biology) and extrinsic factors (shore morphology and oceanography) that affect local supply of kelps and regional hydrodynamics.

Ship hull fouling is recognized as an important vector for the introduction of nonindigenous species (NIS), which has been studied globally but no empirical works exist in the Southeast Pacific. The present study examined fouling organisms on the hulls of three ships in one international Chilean port, and compared them with those on settling plates and natural substrates. Also, genetic analyses were perfomed on the most common NIS recorded in order to explore number and potential origin of the genetic linages found. The highest number of total taxa and NIS were found on ship hulls, with three species identified as NIS in ship samplings. Settling plates displayed the largest number of taxa, with a large abundance of the invasive tunicate Ciona robusta, which also showed high mitochondrial genetic diversity. This study showed that Chilean coasts are subjected to both NIS colonization and propagule pressure through ship hulls. Biosecurity measures should urgently be taken on ship hulls along these coasts.

Chondracanthus chamissoi is part of the diet of coastal people from Peru and is exported dehydrated to Asian countries for direct consumption. Although it is considered endemic to Peru and Chile, its range has extended to distant regions, such as Korea, Japan, and France. Using morphological and molecular approaches, we examined specimens from Peru assigned to C. chamissoi (including the taxon of uncertain status Chondracanthus glomeratus) to improve phylogenetic and geographical information and characterize its morphological variability.Twenty-one localities on the Peruvian coast were sampled, obtaining 102 COI and 27 rbcL sequences. To differentiate both entities, morphological characters such as thallus size, consistency, arrangement of main and secondary axes,branching patterns and location of reproductive structures,were analyzed on 46 specimens. While morphological characteristics are clearly contrasting among the two groups, both COI and rbcL phylogenies revealed a well-supported clade with no genetic differentiation between the two morphologies.Therefore, the phylogenies indicate that C. chamissoi and C. glomeratus form a single taxonomic entity with high morphological variability, large geographic distribution and at least two morphological forms. The smaller form of C. chamissoi can be identified as C. chamissoi f. glomeratus. Such morphological variability can be of interest for future aquaculture development.

Phyllophorella was recently described from two localities on the central coast of Peru (12°S), based on the endemic species Phyllophora (Ph.) peruviana. The genus currently accommodates three species, Phyllophorella (P.) peruviana, P. humboldtiana and P. limaensis. Recent field surveys for Phyllophorella on the central coast of Peru led to the discovery of collections outside the originally reported ranges. Morphological, anatomical, and genetic characterization of the specimens confirms range extensions for P. peruviana to 9° S and 15° S, and P. humboldtiana to 12° S and 15° S. A combined phylogenetic analysis of rbcL and COI-5P gene sequences supports the taxonomic status of these two species and reasserts the genus as monophyletic. Anatomically, the two species differ in nemathecial structure. Phyllophorella peruviana displays dome-shaped and well-defined circular nemathecia, whereas in P. humboldtiana they are irregular and diffuse in form. Mature cystocarps were observed for the first time in Phyllophorella, in P. humboldtiana from Lima and Ica, Peru. Phyllophorella, as well as the other genera classified to the family Phyllophoraceae, have a procarpic sexual system, with a carpogonial branch of three cells; the cystocarp develops a thickened cortex, is immersed in the medulla, and lacks a pericarp and an ostiole. This study demonstrates that field work, together with morphological, developmental, and genetic analyses, are useful methods for improving our understanding of seaweed distributions and systematics.

Harvest pressure on brown macroalgae of the Lessonia genus has increased in recent years in Peru and Chile, due to the high demand from the global hydrocolloid industry. After a taxonomic review, in 2012, the intertidal species Lessonia nigrescens was segregated into two species, being L. berteroana distributed in southern Peru and northern Chile (17-30°S). Based on genetic tools we confirm the identification as L. berteroana and report its presence up to 15°23’S. It is recommended to update the status of the species into Peruvian regulations and scientific publications.