First record of the genus Dudresnaya (Dumontiaceae,Rhodophyta) in New Zealand waters

The genus Dudresnaya is reported for the first time in New Zealand waters. Samples were collected in Bay of Islands, northern New Zealand, on rhodolith beds and at the edge of a rocky reef, between ?5 and ?10 m depth. The species was identified by morphological and anatomical characters as Dudresnaya capricornica and its identity was confirmed by molecular sequence data. This species is characterized by terete radial branches, outer cortical cells cylindrical, presence of hexagonal crystals, lack of annulation and mucilage coat on auxiliary cell branches, oblique division of carpogonium and cystocarps no cleft. The rbcL phylogenetic analysis showed the genus Dudresnaya is strongly supported and sister to taxa in the family Dumontiaceae. This family is also closely related to the families Rhizophillidaceae and Kallymeniaceae. This is the first record of the family Dumontiaceae in New Zealand.     

Neosiphonia flavimarina gen. et sp. nov. with a taxonomic reassessment of the genus Polysiphonia (Rhodomelaceae, Rhodophyta)

Vegetative and reproductive development of Neosiphonia flavimarina gen. et sp. nov. (Rhodomelaceae, Ceramiales) from Bangpo on the western coast of Korea was investigated. This species is superficially similar to Polysiphonia, but differs distinctly from the latter in vegetative and reproductive structures. The plants attach by a solid disk composed of a dense cluster of rhizoids cut off from the pericentral cell wall, and bear erect indeterminate branches producing the lateral-branch initials from successive segments in a spiral arrangement. The procarps have a three-celled carpo-gonial branch. Spermatangial branches are formed on a primary branch of the trichoblasts, terminating in a single or occasionally two large, sterile cells. Tetra-sporangia are produced from the second pericentral cell adjacent to the trichoblast basal cell on indeterminate branches, and arranged spirally. Comparing several taxonomic characters among related genera, Neosiphonia occupies an independent phylogenetic position from Polysiphonia and leads to the conclusion that the genus may have a strong link with Fernandosiphonia which has a unilateral branching system. Relevant nomenclatural changes for several Polysiphonia species are also proposed.     

DUDRESNAYA PUERTORICENSIS SP. NOV. (DUMONTIACEAE,GIGARTINALES, RHODOPHYTA)1

A new species of Dudresnaya is described from Puerto Rico and Georgia. Gametophytes have cylindrical axes, exserted apical cells, rectangular to hexagonal crystals in the axial cells, ellipsoidal outer assimilatory cells, spermatangial mother cells which are terminal or subterminal cells of the subdichotomously branched outer assimilatory branches and auxiliary cells which are indistinguishable in appearance from adjacent, large, deeply staining cells of the auxiliary cell branch. Tetrasporophytes are unknown.     

Dasya adela sp. nov. (Rhodophyta,Ceramiales), an enigmatic new Dasya from a landlocked fjord in southwest Norway

We here report a new Dasya species found in a landlocked fjord or poll in southwestern Norway; Dasya adela sp. nov. The thallus of this species is small (1–3 cm), normally sparsely branched, and its axes are completely covered with cortex cells. The species is set with long (3–4 mm) and flaccid monosiphonous pseudolaterals, and during autumn it showed high growth of adventitious monosiphonous branches. Only a few individuals with tetrasporangia have been recorded, and no sexual reproductive structures have been observed in field collections. In culture stichidia readily developed on the pseudolaterals, with four tetrasporangia per section. The spores showed high mortality. A few sporelings survived in culture, and developed into small and loosely organized filaments with no upright axes. After 2 years in culture a few plants bearing spermatangial branches were observed, but no individuals with carpogonia. The monosiphonous branches are readily shed in culture, attach themselves by rhizoids and rapidly develop into new thalli, some of which have produced tetrasporangial stichidia. Sequences analyses of partial COI and the rbc L gene showed that the new taxon belongs within Dasyoideae. However, no close relationship was found with other European species of Dasya. The new taxon was compared to other Dasya taxa with which it shared a number of selected characters, but none of these taxa shared all characters of the new Dasya.     

BATRACHOSPERMUM HETEROCORTICUM SP. NOV. AND POLYSIPHONIA SUBTILISSIMA (RHODOPHYTA) FROM FLORIDA SPRING-FED STREAMS1

Polysiphonia subtilissima Mont. Is reported for the first time from a freshwater environment. The presence of four pericentral cells, subdichotomous branching, apical trichoblasts and rhizoids arising from pericentral cells combined with a lack of cortication and reproductive cells is consistent with marine populations of this species. The range of filament length is 1.4–4.7 cm. Branch diameters are 38–76 μm and pericentral cell lengths are 58–125 μm. Batrachospermum heterocorticum sp. nov. is distinguished primarily by a developmental change in cortical filaments from typical cylindrical cells (5.0–7.9 μm diam in initial stages to enlarged, elliptical cells (12.9–24.1 μm diam) in mature axes. Another unique feature of this species is carpogonia with cylindrical, pedicellate trichogynes on stringht carpogonial branches in mid to outer portions of lateral whorls. Other characteristics of B. heterocorticum include the following: olive-green color, 2–6 cm length, dichotomous to trichotomous fascicles in 4–7 tiers, 385–647 μm whorl diameters, 109–198 μm carpospore diameters and relatively small “chantransia” filaments.     

Vegetative and reproductive morphology of Herpochondria corallinae (Martens) Falkenberg and H. elegans (Okamura) Itono (Ceramiaceae,Rhodophyta) from Korea

The vegetative and reproductive morphology of two epiphytic Herpochondria species, H. corallinae (Martens) Falkenberg (the type species) and H. elegans (Okamura) Itono from Korea were investigated. They are bilaterally compressed and alternate-distichously branched, and lateral branches are produced by oblique divisions of the apical cell. Procarps are restricted to the first periaxial cell of the branches. Spermatangial mother cells produce one or two spermatangia. H. corallinae forms tetrasporangia on six periaxial cells, whereas H. elegans has them on only the two lateral periaxial cells. The prostrate habit, the production of six periaxial cells in opposite pairs, and tetrasporangial stichidia are confirmed as diagnostic characters of the genus Herpochondria.     

Morphology of Laurencia clavata and L. elata (Ceramiales,Rhodophyta) in relation to generic circumscription in the Laurencia complex

Laurencia Lamouroux (Rhodophyta) was recently separated into three genera–Laurencia, Chondrophycus (Tokida et Saito) Garbary et Harper and Osmundea Stackhouse – each of which was newly defined based on vegetative and reproductive structures. In this study, the previously unknown vegetative and reproductive morphology of two Australian endemic species of Laurencia, L. clavata Sonder and L. elata (C. Agardh) Harvey, was studied, particularly in the context of the revised generic delineation. These species exhibit vegetative axes with four pericentral cells and trichoblast-type spermatangial development. Tetrasporangia are abaxially produced from the existing third and fourth pericentral cells. L. clavata has terete thalli with distinctive verticillate branching and is similar to Chondria C. Agardh, rather than to Laurencia, in having an unusually marked constriction at the base of the branches and starch accumulation in subcortical and medullary cells. Compared to Laurencia, apical cells of this species exhibit a less oblique division ; the resulting recognizable axial cell rows extend somewhat below the branches, and particularly at a young stage they are also clear throughout branchlets. However, other vegetative and spermatangial structures show that L. clavata is more closely allied to Laurencia than to Chondria, and it is placed in Laurencia. By contrast, L. elata exhibits morphology typical of Laurencia and is characterized by large, robust, compressed thalli with fastigiately distichous branching and an extensive secondary cortex. Furthermore, it appears to be distinct from similar species in sometimes having a parasitic species of Janczewskia Solms-Laubach (Rhodophyta). Taxonomy of Laurencia is discussed on the basis of these and previous studies.     

Two new species of Gelidium (Rhodophyta, Gelidiales), Gelidium tenuifolium and Gelidium koshikianum, from Japan

Two new marine red algae, Gelidium tenuifolium sp. nov. and Gelidium koshikianum sp. nov. (Gelidiales, Gelidiaceae) are described from Japan. Gelidium tenuifolium with large‐sized thalli (up to 30 cm tall) is distinguished from other species with such thalIi by the production of wide, flattened and thin branches (up to 2 mm wide and 60–80 urn thick), the presence of an apical depression and simple determinate branches. Gelidium koshikianum with middle‐sized thalli (5–8 cm tall) is distinguished from other species with such thalli by having wide axes (up to 2.5 mm wide) and short (2.0–3.2 mm), unbranched, second‐ and third‐order branches issuing at short intervals (0.8–1.4 mm). In phylogenetic analyses of rbcL sequences, four Gelidium species that are chiefly distributed in Japan including G. tenuifolium were clustered together with 99% bootstrap value (Japanese Gelidium‐complex clade). Gelidium linoides Kützing came to the position of the sister group to G. tenuifolium with 99% bootstrap value. There were four substitutions (0.3% divergence) between G. linoides and G. tenuifolium sequences. Gelidium koshikianum and Gelidium allanii Chapman were clustered together with 100% bootstrap value and they came to the position of the sister group to the Japanese GeIidium‐complex clade with 83% bootstrap value. There were six substitutions (0.4% divergence) between G. koshikianum and G. allanii sequences.     

竹亚科单枝竹属芸香竹花枝和花特征补充描述

繁殖器官在竹类植物的分类学研究中具有重要意义,研究组在广西马山县观察到竹亚科单枝竹属芸香竹正在开花,该文根据观察到的开花状况和采集到的标本解剖观察结果,对其花枝和繁殖器官特征做了详细的中文及拉丁文补充描述。经对比芸香竹与属内已知繁殖器官结构的单枝竹和小花单枝竹的繁殖器官,3个竹种有相同的繁殖器官结构特征,但在小花数目和大小等方面具有差异。繁殖器官比较表明该属竹种的繁殖器官对喀斯特地貌环境有特殊的适应性,也支持依据营养器官差异划分为3个独立竹种。     

Phenology of Paralemanea mexicana (Batrachospermales,Rhodophyta) in a high‐altitude stream in central Mexico

The morphology and phenology of Paralemanea mexicana (Kützing) Vis et Sheath was evaluated seasonally in a fifth order high‐altitude stream in central Mexico. The gametophytes grew during oligotrophic and eutrophic conditions, and during particular microhabitat conditions: high current velocity (40–240 cm s^?1), low to medium irradiance (5–973 μmol photons m^?2 s^?1), and shallow depth (1–30 cm). The abundance of gametophytes was positively correlated with low temperature, high current velocity and concentrations of soluble reactive phosphorus. Interestingly, monoecious gametophytes formed two types of branches, true branches with sympodial pattern originating from meristematic cells in variable number, and abundant false branches produced during the development of the ‘Chantransia’ stage in the surface of the gametophyte or by uniseriate filaments arising within the thallus lumen. These filaments generally produce gametophytes and suggest that they could support the germination of carpospores. The frequently whorled branches are the result of a false branching pattern and are exclusive to P. mexicana. These morphological and reproductive characteristics appear to be biomechanical adaptations to avoid detachment and increase reproductive success. Efficient reproductive strategies of P. mexicana observed in this study can be interpreted as adaptations to successfully colonize streams; however, these features may not have been common in the study region due to restricted microhabitat conditions and geographic isolation.     

ALGAE FROM CABO FRIO UPWELLING AREA. 2. GELIDIOCOLAX PUSTULATA (GELIDIACEAE,RHODOPHYTA): AN UNUSUAL NEW PUTATIVE PARASITIC SPECIES1

A new species of Gelidiocolax Gardner, G. pustulata Oliveira and Yoneshigue, is described in the tropical western Atlantic from Brazil. The species usually grows on the basal portion of the main axis of Pterocladia capillacea (Gmelin) Bornet et Thuret. Abundant material was collected mainly from November to March at Cabo Frio Island, in the northeast part of the State of Rio de Janeiro, a marine area well known for its upwelling. Infection by the putative parasite seems to damage the host tissue, stimulating the development of a “gall-like” structure that leads to the outgrowth of adventitious branches. The new species has the vegetative features and reproductive structures of the genus Gelidiocolax. It can be distinguished from the other Gelidiocolax species mainly on the basis of its position on the host, size of pustula, the tetrasporangia and the development of spermatangia. Studies of this new taxon support the placement of Gelidiocolax in the Gelidiaceae and not the Choreocolacaceae, as has been suggested in the literature.     

THE GENUS PLATOMA (GIGARTINALES,RHODOPHYTA) WITH A DESCRIPTION OF P. ABBOTTIANA SP. NOV.1

Platoma abbottiana (Gymnophlaeaceae; Gigartinales), a new species of benthic red algae, is described from Isla Mejía and is the second member of this genus reported from the Gulf of California, Mexico. Vegetative anatomy and reproductive details of the carpogonial and auxiliary cell branches of the new species are described and illustrated. Geographical distributions of the seven previously described Platoma species are given. Their distinguishing morphological characteristics are compared to those of the new species. The correct time and place of valid publication of the generic name, Platoma, and some of its binomials are discussed.     

Distribution of plant‐dwelling spiders: Inflorescences versus vegetative branches

Abstract The influence of the architecture of vegetative branches on the distribution of plant‐dwelling spiders has been intensively studied, and the effects on the aggregation of individuals in several spider species on plants include variation in prey abundance, availability of predator‐free refuges and smoother microclimate conditions. The emergence of inflorescences at the reproductive time of the plants changes branch architecture, and could provide higher prey abundance for the spiders. The distribution of spiders between inflorescences and vegetative branches was compared on four widespread plant species in a Brazilian savannah‐like system. Inflorescences attracted more spiders than vegetative branches for all plant species sampled. The influence of branch type (inflorescence and vegetative) on spider distribution was also evaluated by monitoring branches of Baccharis dracunculifolia DC. in vegetative and flowering periods for 1 year, and through a field experiment carried out during the same period where artificial inflorescences were available for spider colonization. Artificial inflorescences attached to B. dracunculifolia branches attracted more spiders than non‐manipulated vegetative branches for most of the year. However, this pattern differed among spider guilds. Foliage‐runners and stalkers occurred preferentially on artificial inflorescences relative to control branches. The frequencies of ambushers and web‐builders were not significantly different between treatment and control branches. However, most ambush spiders (65%) occurred only during the flowering period of B. dracunculifolia, suggesting that this guild was influenced only by natural inflorescences. The experimental treatment also influenced the size distribution of spiders: larger spiders were more abundant on artificial inflorescences than on vegetative branches. The hypothesis that habitat architecture can influence the spider assemblage was supported. In addition, our observational and experimental data strongly suggest that inflorescences can be a higher quality microhabitat than non‐reproductive branches for most plant‐dwelling spiders.     

Reproductive features and gonad development cycle of the soft bottom-gravel gorgonian Leptogorgia sarmentosa (Esper, 1791) in the NW Mediterranean Sea

Abstract

Leptogorgia sarmentosa (Cnidaria: Octocorallia) is a common soft bottom-gravel gorgonian in the northwestern Mediterranean Sea. This study examined the annual reproductive cycle of a L. sarmentosa. population at a depth of 30 m, and further determined the sex ratio, the intra-colonial gonadal output variability and the age at first reproduction. L. sarmentosa was gonochoric and the population studied was characterized by a sex ratio slightly biased towards female colonies (1 male:1.6 female). Secondary branches had higher polyp fertility (number of gonads per polyp) compared to primary branches, but because of the number of polyps on the former, most of the sexual effort was actually contributed by the primary branches, as in other gorgonian species. Male colonies became fertile above a height of 21 cm, but female colonies had gonads even in the 1–10 cm height class. Spawning occurred between late August and early September, although there was no direct observation of broadcast spawning or surface brooder strategy. The maximum gonad size was 550 μm in males and 500 μm in females, with a mean diameter of 270 μm for spermaries, and 190 μm for eggs. The number of gonads per polyp prior to spawning reached 4–5 spermaries polyp!1 in male colonies, and 3–4 eggs polyp!1 in female colonies. Spawning did not appear to be synchronized with the full moon. L. sarmentosa appeared to have a different reproductive strategy to other Mediterranean gorgonians (living on hard bottom substrata), probably because of its different habitat preferences and biological (morphology, diet, prey capture rates, growth, biochemical levels) features.     

Phenology of Sargassum spp. in Tung Ping Chau Marine Park, Hong Kong SAR, China

Eight species of the brown alga Sargassum have been recorded from Tung Ping Chau Marine Park in Hong Kong and the phenology of four of these was monitored from 1996 to 2000. All four species followed a typical growth cycle of Sargassum species reported elsewhere but with some annual variations. For S. hemiphyllum, the maximum mean (±SD) plant length, ranging from 38.5 ± 10.5 to 61.9 ± 19.9 cm, was recorded in January to March. The peak reproductive season was also mainly in February to March with up to 89% of the plants being reproductive. Some plants, however, remained reproductive until May. For. S. henslowianum, the maximum mean plant length, ranging from 45.5 ± 25.5 to 77 ± 24.8 cm, was recorded mainly in November to January. The peak reproductive season was in November to February with up to 100% of the plants being reproductive. For S. siliquastrum, the maximum mean plant length, ranging from 48.2 ± 29.9 to 63.4 ± 22.1 cm, was also recorded mainly in January. The reproductive plants were found mainly between late December and mid February with up to 98% of the plants being reproductive. For. S. patens, the maximum mean plant length ranging from 87.6 ± 62.4 to 118.7 ± 41.3 cm was recorded in January to March. Reproduction of this species was not monitored. Changes in water temperature over seasons were likely to be critical in affecting the phenological patterns of these species.     

COMPONENTS OF REPRODUCTIVE EFFORT AND YIELD IN GOLDENRODS

Four components of reproductive yield (the weight of reproductive tissue) were examined in relation to their effect on reproductive effort and their relative contributions to reproductive yield in five species of goldenrods (Solidago, Compositae). The yield components were number of flowing stems per plant, number of flowering branches per stem, number of flowering heads per branch, and number of seeds per seed head. Individuals within populations increase their reproductive effort by increasing their reproductive weight, not by decreasing their vegetative weight. Each species shows a different pattern of positive correlations of yield components with reproductive yield and reproductive effort, indicating that each species has its own mechanisms for regulating reproduction. The yield components were not significantly intercorrelated.     

Strategies for Gardening Denuded Coral Reef Areas: The Applicability of Using Different Types of Coral Material for Reef Restoration

Recreational and other human activities degrade coral reefs worldwide to a point where efficient restoration techniques are needed. Here we tested several strategies for gardening denuded reefs. The gardening concept consists of in situ or ex situ mariculture of coral recruits, followed by their transplantation into degraded reef sites. In situ nurseries were established in Eilat's (Northern Red Sea) shallow waters, sheltering three types of coral materials taken from the branching species Stylophora pistillata (small colonies, branch fragments, and spat) that were monitored for up to two years. Pruning more than 10% of donor colonies' branches increased mortality, and surviving colonies displayed reduced reproductive activity. Maricultured isolated branches, however, exceeded donor colony life span and reproductive activity and added 0.5–45% skeletal mass per year. Forty‐four percent of the small colonies survived after 1.5‐year mariculture, revealing average yearly growth of 75 ± 32%. Three months ex situ maintenance of coral spat (sexual recruits) prior to the in situ nursery phase increased survivorship. Within the next 1.5 years, they developed into colonies of 3–4 cm diameter. Nursery periods of 2 years, 4–5 years, and more than> 5 years have been estimated for small colonies, spat, and isolated branches, respectively. These and other results, including the possible use of nubbins (minute fragments the size of a single or few polyps), are discussed, revealing benefits and drawbacks for each material. In situ coral mariculture is an improved practice to the common but potentially harmful protocol of direct coral transplantation. It is suggested that reef gardening may be used as a key management tool in conservation and restoration of denuded reef areas. The gardening concept may be applicable for coral reefs worldwide through site‐specific considerations and the use of different local coral species.     

Foliage Density of Branches and Distribution of Plant‐Dwelling Spiders1

We compared the abundance of foliage‐living spiders among seven widespread plant species comprising a gradient of levels of structural complexity in a tropical savannah‐like region in southeastern Brazil. Spider abundance among plant species was positively related to the foliage density of their branches. A field experiment using artificial branches was carried out to isolate foliage density effects on spider abundance, thus controlling both biomass and texture effects. Artificial branches were attached to branches of three plant species with similar foliage density, Baccharis dracunculifolia, Diplusodon virgatus, and Microlicia fasciculata. Two treatments were set up: artificial branches with higher foliage density attracted more spiders than those with lower foliage density. The guild structure of hunting spiders was compared among vegetative branches of three plant species with different levels of foliage density: B. dracunculifolia, D. virgatus, and Bidens gardneri. Stalker, and ambusher spiders were more abundant on branches of B. dracunculifolia, which had the highest foliage density. Foliage‐runners constituted the dominant guild on D. virgatus and B. gardneri, which have lower foliage density branches. Our results suggest that branch architecture is the most important factor determining the abundance of plant‐dwelling spiders in the study area independently of branch biomass, leaf surface area or texture.     

Genomic analyses reveal natural selection on reproduction related genes between two closely related Populus (Salicaceae) species

Identifying the factors that cause reproductive isolation and their relative importance in species divergence is crucial to our understanding of speciation processes. In most species, natural selection is commonly considered to play a large role in driving speciation. Based on whole genome re-sequencing data from 27 Populus alba and 28 Populus adenopoda individuals, we explored the factors related to reproductive isolation of these two closely related species. The results showed that the two species diverged ~5–10 million years ago (Ma), when the Qinghai–Tibet Plateau reached a certain height and the inland climate of the Asian continent became arid. In highly differentiated genomic regions, the relative divergence (F_ST) and absolute divergence (d_xy) were significantly higher than the genomic background, θπ and shared polymorphisms decreased whereas fixed differences increased, which indicated that natural selection played a key role in the reproductive isolation of the two species. In addition, we found several genes that were related to reproduction that may be involved in explaining the reproductive isolation. Using phylogenetic trees resolved from haplotype data of Populus tomentosa and P. adenopoda, the maternal origin of P. tomentosa from P. adenopoda was likely to be located in Hubei and Chongqing Provinces.     

Reproductive morphology of Gastroclonium pacificum (Champiaceae,Rhodymeniales) from Japan

Morphological studies were undertaken on Gastroclonium pacificum (E.Y. Dawson) C.F. Chang et B.M. Xia (Champiaceae, Rhodymeniales) from Japan. We describe the details of male reproductive structures, the procarp and early post‐fertilization stages. This species has a solid axis, with both tetrasporangia and polysporangia, spermatangia are cut off from spermatangial parent cells, and a procarp is composed of a 4‐celled carpogonial branch and two 2‐celled auxiliary cell branches. The mature cystocarp lacks a conspicuous ostiole, a characteristic of the genus Gastroclonium. The most distinctive characteristic of the species is the tela arachnoidea, which is lacking in other species of Gastroclonium.