Isabel Maneiro

Identification of subpopulations in pelagic marine fish species using amino acid composition

The spatial stock complexity of marine fish species requires that population structure is taken into account in fisheries management. The aim of this study was to determine whether the amino acid composition (AAC) of the adult fish allows the identification of subpopulations within the stock. During a cruise in November 2003 along the entire Mediterranean coast of Spain, individuals were collected of the following pelagic species: Sardina pilchardus, Sardinella aurita, Engraulis encrasicolus, Trachurus trachurus, Trachurus mediterraneus, Scomber scombrus and Scomber colias. Individuals of S. pilchardus and E. encrasicolus were also collected from the waters of the Strait of Sicily in 2002 and 2003. The AAC of the fish eyes was seen to be species specific, and therefore, the differences in AAC among species may be based on inherited characters. Moreover, a clear differentiation was seen between the Spanish and Sicilian populations of S. pilchardus and E. encrasicolus. Furthermore, in the Spanish waters of the Mediterranean Sea, discriminant analysis revealed a substantial separation between the northern and southern subpopulations of S. pilchardus, S. aurita and E. encrasicolus. Temporal variations in AAC within species in each area were lower than the spatial variations observed among areas for each species, probably reflecting the influence on the AAC of the contrasting environmental characteristics of each area. Our results indicate that the ACC of the eyes in adult fish is a good tool for discriminating among subpopulations in pelagic marine fish species.

MICROSATELLITE DEVELOPMENT IN RHODOPHYTA USING HIGH-THROUGHPUT SEQUENCE DATA 1

Shotgun genome sequencing is rapidly emerging as the method of choice for the identification of microsatellite loci in nonmodel organisms. However, to the best of our knowledge, this approach has not been applied to marine algae so far. Herein, we report the results of using the 454 next‐generation sequencing (NGS) platform to randomly sample 36.0 and 40.9 Mbp (139,786 and 139,795 reads, respectively) of the genome of two red algae from the northwest Iberian Peninsula [Grateloupia lanceola (J. Agardh) J. Agardh and a still undescribed new member of the family Cruoriaceae]. Using data mining tools, we identified 4,766 and 5,174 perfect microsatellite loci in 4,344 and 4,504 sequences/contigs from G. lanceola and the Cruoriaceae, respectively. After conservative removal of potentially problematic loci (redundant sequences, mobile elements), primer design was possible for 1,371 and 1,366 loci, respectively. A survey of the literature indicates that microsatellite density in our Rhodophyta is at the low end of the values reported for other organisms investigated with the same technology (land plants and animals). A limited number of loci were successfully tested for PCR amplification and polymorphism finding that they may be suitable for population genetic studies. This study demonstrates that random genome sequencing is a rapid, effective alternative to develop useful microsatellite loci in previously unstudied red algae.

MULTISCALE GENETIC STRUCTURE OF AN ENDANGERED SEAWEED AHNFELTIOPSIS PUSILLA (RHODOPHYTA): IMPLICATIONS FOR ITS CONSERVATION(1).

Although marine macroalgae have recently entered the lists of endangered species, conservation efforts are still limited by a lack of data, particularly for naturally rare species. One example is the turf‐forming Ahnfeltiopsis pusilla (Mont.) P. C. Silva et DeCew. Albeit cataloged as vulnerable in the Northwest Iberian Peninsula (NWIP), where it occurs only at five enclaves separated by 1,200 km from the closest recorded presence of the species, nothing is known about its genetic diversity and population connectivity. We used amplified fragment length polymorphism (AFLP) and sequences of the intergenic region between the mitochondrial cytochrome oxidase subunit 2 and subunit 3 genes (cox2‐3) to investigate its genetic structure at large (1,200 km), regional (<125 km), fine (<250 m), and patch (<1 m) scales. While cox2‐3 variability was too low for the intraspecific study, AFLP revealed that most of the genetic diversity was due to differences between populations. Locally, genetic diversity was always low, and clones were frequent, suggesting that asexual reproduction may be common; patches of turf, however, often were composites of various genetic individuals. Genetic structure at local, regional, and large scales indicated that A. pusilla is a poor disperser, and an assignment test found no evidence of real‐time dispersal between NWIP sites. Therefore, it is proposed that the five NWIP enclaves are designated independent management units (MUs). Bayesian‐clustering approaches suggested that the three southernmost sites are particularly valuable for conservation since they concentrate most of the genetic heritage of A. pusilla in NWIP. Our study shows that the approaches of conservation genetics may provide useful insights for endangered seaweeds.

A new taxonomic interpretation of the type of Plocamium cartilagineum (Plocamiales, Florideophyceae) and its consequences

A detailed study of the type specimen of Plocamium cartilagineum and other original material of European species of Plocamium revealed that the nomenclatural reorganization proposed by Saunders & Lehmkuhl in 2005 must be revised. The main consequences of the new interpretation are: (1) the use of Plocamium lyngbyanum to name their molecular entity EUR1 (previously considered to be equivalent to P. cartilagineum s.s.); and (2) adopting P. cartilagineum for their molecular entity EUR2, which renders P. subtile Kützing a taxonomic synonym. Using a combination of morphological, anatomical and molecular information (barcoding), we conclude that the colour and consistency of the thallus, the number of ramuli per series, the morphology and arrangement of the tetrasporangial stichidia, the length of the tetrasporangia, and the type of habitat are the most reliable characters of classical taxonomy for discriminating between the species of Plocamium occurring in northern Europe.

Morphology and systematics of Calliblepharis hypneoides, sp. nov. (Cystocloniaceae, Rhodophyta) from the Atlantic Iberian Peninsula

Calliblepharis hypneoides Díaz-Tapia, Bárbara & Hommersand, sp. nov., is described based on plants collected in sand-covered rocks from southern France to Portugal. Calliblepharis hypneoides is distinguished by a terete thallus, forming an extensive basal system of entangled prostrate axes that bear few irregularly branched upright axes, an inner structure consisting of a central axial filament surrounded by 5–7 filaments of elongated cells, a continuous outer cortex, spermatangial parent cells transformed from outer cortical cells and bearing spermatangial filaments three or four cells long, a single gonimoblast initial cut off from the inner side of the auxiliary cell, with the young carposporophyte consisting of a central reticulate network of interconnected cells linked inwardly to a cluster of basal nutritive filaments and forming gonimoblasts outwardly that bear chains of carposporangia in non-ostiolate cystocarps arising on main axes and branches, and tetrasporangia terminal in sori on ultimate branchlets. These features are characteristic of Calliblepharis and molecular analyses confirm this relationship. In all phylogenetic analyses of cox1, rbcL and SSU sequences, C. hypneoides was consistently distinct from congeners. In both rbcL and SSU trees, its sister relationship to other species was unresolved, probably due to missing species or the exclusion of undescribed species. This is the first report on the systematics of Calliblepharis using three molecular markers.

Pseudopolyides furcellarioides gen. et sp. nov. (Gigartinales, Rhodophyta) an erect member of the Cruoriaceae based on morphological and molecular evidence

Bárbara I., Gallardo T., Cremades J., Barreiro R., Maneiro I. and Saunders G.W. 2013. Pseudopolyides furcellarioides gen. et sp. nov. (Gigartinales, Rhodophyta) an erect member of the Cruoriaceae based on morphological and molecular evidence. Phycologia 52: 191–203. DOI: 10.2216/12-040.1 Pseudopolyides furcellarioides gen. et sp. nov. (Gigartinales, Rhodophyta) was described from the Atlantic coasts of the northern Iberian Peninsula based on morphological and molecular evidence. This plant was found growing in the lower intertidal to the upper subtidal of moderately exposed rocky coasts, the bases anchored to rocks and often covered by sand. Thalli were perennial, terete, dichotomously branched and erect from a mammillate crustose holdfast. Fronds were multiaxial with a compact filamentous medulla, a densely pseudoparenchymatous inner cortex and an anticlinal outer cortex. Gametophytes were dioecious and isomorphic to tetrasporophytes. Spermatangia were superficial on swollen branch tips. Gonimocarps were spindle-shaped and directed to the thallus interior, while tetrasporangia were zonate. The habit and internal structure resembled those of both Polyides rotundus (characterized by crustose holdfasts, dichotomous or trichotomous branching and similar longitudinal section) and Furcellaria lumbricalis (distinguished by internal gonimocarps and zonate tetrasporangia). All three species occasionally occurred sympatrically in the Iberian Peninsula and were easily misclassified. Molecular phylogenetic analyses placed Pseudopolyides furcellarioides within the previously monogeneric Cruoriaceae, making it the first non-crustose representative of this family.