Kappaphycus Species Research Articles

Niche comparison and range shifts for two Kappaphycus species in the Indo-Pacific Ocean under climate change

Nowadays, eucheumatoids lead the rankings in globally cultivated seaweed production, including the seaweeds Kappaphycus alvarezii and Kappaphycus striatus. Eucheumatoids have declined in biomass over recent years, and climate change is regarded as one of the important factors. Thus, it is urgent to investigate the range dynamics of Kappaphycus under climate change. Considering its high practical relevance for conserving biodiversity, the niche conservatism hypothesis was tested between the two species through ecological niche modeling (ENM), ordination, and hypervolume approach which quantify the extent of niche overlap. In this study, we sifted the best-performing algorithm - Maxent and tuned parameters for fitting the distribution of both Kappaphycus species, compared their geographical distribution patterns, and predicted their range dynamics under climate change. All three methodological approaches indicated significant niche differences in both geographical and environmental space between the two Kappaphycus species. Our models predicted that range shifts mainly induced by rising sea surface temperature are likely to differ between two Kappaphycus species, with K. striatus suffering much range contraction (359,448 km2 in 2100s RCP8.5). By the year 2100, both Kappaphycus species are forecast to lose suitable habitats along most of the coastline of Southeast Asia under the RCP8.5 scenario. K. alvarezii is predicted to expand its distributions (96,429 km2) under the RCP2.6 scenario by the year 2100, suggesting resilience to mild global warming. Our study enhances the understanding of Kappaphycus aquaculture, and is conducive to the sustainable development of tropical seaweed by stressing the importance of conservation and investigation under climate change.

The complete mitochondrial genome of a wild-collected Kappaphycus malesianus (Solieriaceae, Rhodophyta)

Kappaphycus malesianus is a red seaweed farmed primarily for its carrageenan, a polysaccharide important in the food and pharmaceutical industries. Among the commercially cultivated Kappaphycus species, only K. malesianus has no mitogenome data available. Here, we assembled the mitochondrial genome of K. malesianus from next-generation sequencing data. The circular mitogenome consisted of 25,250 base pairs (bp) with a GC content of 30.25%. These values were comparable to previously sequenced solieriacean mitogenomes. Structural features, such as the stem-loop and hairpin, which were previously reported in other rhodophytes mitochondrial DNA, were also identified. The annotated genes (24 protein-coding genes, 24 tRNA genes, and 2 rRNA genes) were arranged in an order similar to the other available solieriacean mitogenomes. Lastly, phylogenetic analysis using 23 predicted protein domains showed the sister relationship of K. malesianus with other Kappaphycus species.

Use of Brown Seaweed Extracts as Bio-fertilizers and their Effects on the Carrageenan Yield, Ice-ice Disease Occurrence, and Growth Rate of the Red Seaweed Kappaphycus striatus

Kappaphycus striatus is one of the most important eucheumatoid species that is widely farmed worldwide. In the southern Philippines, where the initial farm was established, sluggish growth of farmed Kappaphycus species brought about by the poor quality of planting materials and extensive farming resulting in unproductive farms and frequent ice-ice outbreaks have been a hindrance in increasing the seaweed production. As a result, farmers have led to the application of inorganic fertilizers as nutrient enrichment for Kappaphycus. However, inorganic or chemical fertilizers always pose negative impacts on the environment. Hence, in this study, a preliminary investigation on the potential use of extracts of brown seaweeds Sargassum cristaefolium and Turbinaria conoides as bio-fertilizers was tested on K. striatus for their growth rate, carrageenan yield, and ice-ice disease occurrence. Seaweed liquid extracts (SLE): S. cristaefolium (SC), T. conoides (TC), combination of SC and TC (MX), and control (C) were utilized as bio-fertilizers for K. striatus. SLE-enriched K. striatus seedlings were cultivated in a seaweed farm using the fixed-off bottom method for 45 days. Results revealed that the specific growth rates of all SLE treatments were significantly higher than no SLE treatment at day 45. The percentage of ice-ice disease and the yield of carrageenan did not differ among treatments. Enrichment of K. striatus using SLE of two selected brown seaweeds before out-planting could improve growth rates while not affecting the ice-ice disease occurrence and carrageenan yield. Hence, formulated SLE from brown seaweeds S. cristaefolium and T. conoides can be used as potential bio-fertilizers for Kappaphycus cultivation.

Abundance of marine-derived fungi in nutrient-enriched Kappaphycus species

The occurrence of ice-ice disease is among the main issues affecting Kappaphycus production. The abiotic and biotic factors have major contributions to causing this disease. As biotic factors, marine-derived fungi (MDF) are known to be capable of causing the ice-ice disease. In this study, we determined the abundance of MDF from both healthy and ice-ice-infected nutrient-enriched Kappaphycus alvarezii and K. striatus in the seaweed farms of Tongehat, Sibutu, Tawi-Tawi, southern Philippines, following serial dilution procedure using malt extract agar. Results revealed that the abundance of MDF in ice-ice-infected nutrient-enriched K. alvarezii (3.04 x 10^4 CFU g⁻¹) had shown higher significance (p<0.05) when compared with healthy nutrient-enriched K. alvarezii (3.32 x 10^3 CFU g⁻¹). Similarly, the abundance of MDF in ice-ice-infected nutrient-enriched K. striatus (9.31 x 10^3 CFU g⁻¹) also appeared to have higher significance (p<0.01) than healthy nutrient-enriched K. striatus (6.10 x 10^2 CFU g⁻¹). In terms of seaweed species comparison, the abundance of MDF in healthy nutrient-enriched K. alvarezii had a higher significance (p<0.05) than in healthy nutrient-enriched K. striatus, and the abundance of MDF in ice-ice-infected nutrient-enriched K. alvarezii also had higher significance (p<0.05) than ice-ice-infected nutrient-enriched K. striatus. The great number of MDF in ice-ice-infected nutrient-enriched Kappaphycus suggests that MDF may be potential causative agents and have the capability of inducing ice-ice disease in farmed nutrient-enriched Kappaphycus.

Phylogeny and genetic diversity of the Philippine eucheumatoid genus Mimica (Solieriaceae, Rhodophyta), and the proposal for Kappaphycopsis gen. nov. to include the anomalous species of Kappaphycus, K. cottonii

ABSTRACT The term ‘eucheumatoids’ designates a group of genera in the family Solieriaceae that are the source of some of the most valuable algal products in cultivation. While economically important in the tropics, much of its taxonomy is yet to be fully resolved. The eucheumatoid species Mimica arnoldii is a Batesian mimic of corals that was recently transferred to its own genus from Eucheuma based primarily on peculiarities of habit and a lack of medullary rhizoids, in contrast to the generitype Eucheuma denticulatum that has the latter. We studied the diversity of Mimica arnoldii from samples collected in the Philippines to determine their genetic variation, relationships to other eucheumatoids, and whether its two distinct morphological expressions, which have been named as varieties, are genetically different. We produced a phylogeny using a three-gene concatenated dataset, and used the variable mitochondrial cox2-3 spacer to determine intraspecific variation and the degree of correlation between sequence-variation and varietal status. Our results showed that Mimica is a distinct genus, and that intra-specific molecular data did not correspond to the morphology-based varieties, although it did correlate with geographical distribution. Our results also indicate that Kappaphycus, as presently circumscribed, contains species with (Kappahycus alvarezii, K. striatus and K. malesianus) and without (Kapppahycus cottonii) internal medullary hyphal core, and that K. cottonii is sister to the remaining Kappaphycus species. We thus propose Kappaphycopsis gen. nov. for K. cottonii for the species of Kappaphycus without internal medullary rhizoids (anaxiferous).

Potential of Seaweed (&lt;i&gt;Kappaphycus alvarezii&lt;/i&gt;) as a Particleboard

Recently, the utilization of lignocellulosic materials to produce eco-friendly products is very promising as biodegradable reinforcing elements for composite materials like particleboards and medium density fiberboards. The growing shortage of wood supply has also led to the development of suitable alternative materials for construction. For this reason, the industry is working to develop high-efficiency green materials including the use of seaweed. This research is aims to study the potential of seaweed from Kappaphycus species as a particleboard. Several different target densities were produced according to following proportions: seaweed particles from 150 to 200 grams and UF resin from 15% to 20%. Mechanical properties including internal bonding and bending testing were tested in this study. Samples were also investigated by utilizing microscopy for surface characterization. The outcome showed that seaweed particleboard with highest amount of seaweed particle and UF resin resulted in highest MOE, MOR and internal bonding strength values with results 457.47, 1.5, and 4.73 MPa, respectively. According to Japanese Standard, Internal bonding (IB) strength values for all the samples met the IB requirements of the standards for general uses. Thus, seaweed particle has potential to be an alternative raw material in the manufacture of particleboards.

Micropropagation and sea-based nursery growth of selected commercial Kappaphycus species in Penang, Malaysia

The increasing demands for seaweeds have promoted the designation of the seaweed industry as the third Entry Point Project (EPP) under the National Key Economic Area (NKEA) initiative of the Economic Transformation Programme (ETP) of the Malaysian government. The farming of carrageenophytes has emerged as a successful enterprise and provides a promising alternative livelihood option for low-income coastal communities in several countries. However, over time, the productivity of the red seaweed crop has declined in some regions due to sourcing of seedlings from single, selected genetic stocks considered to have initially higher yield potential but which resulted in strain fatigue or loss of vigour. To circumvent the crop productivity issues arising from clonal propagation, the raising of planting materials from the development and successful micro-propagation of Kappaphycus has been initiated in order to support the sustainability of selected, farmed carrageenophytes. Three species of Kappaphycus (K. alvarezii (to include 2 strains—brown and green) K. malesianus (aring-aring) and K. striatus) were used in the present study to optimize the use of Ascophyllum Marine Plant Extract Powder (AMPEP K+) which had previously been demonstrated to be effective as a culture medium ingredient, acting as a biostimulant, when applied with the addition of terrestrial plant growth regulators (PGRs). The optimum combination of 3 mg L−1 AMPEP K+ + PGRs was used in out-planting the microplantlets to a sea-based nursery. Salinity and turbidity were found to be positively correlated with growth rates in open water. The use of the brown seaweed-derived extract acting as a biostimulant and as the main ingredient of the cost-effective culture medium for the micro-propagation for all four strains of Kappaphycus tested was highly encouraging, so much so that the treatment has the potential to be promoted as a generic protocol for the economic and commercial mass production of new plantlets (asexual seedlings) which are urgently required for Malaysian seaweed farming to meet its fullest potential.

Antioxidant and antibacterial activity of red seaweed Kappaphycus alvarezii against pathogenic bacteria

Seaweeds can produce variety of bioactive components for the benefits of humans. Malaysia is one of the countries to produce red seaweeds, which are popular secondary metabolites. Kappaphycus species, largest tropical red algae exhibit the high growth rate. It was reported that its biomass can grow double in just 15 to 30 days. Therefore, this investigation emphasized on two extraction methods such as hot water and ethanolic Soxhlet extraction to extract the bioactive compounds from Kappaphycus alvarezii. Both of theseextractions were screened to produce antimicrobial and antioxidants compounds. Total phenolic content and ferric reducing assays were employed to quantify antioxidant properties. Whereas, the disc diffusion assays were used to study antibacterial activity. The results reported the highest phenolic content for ethanolic extract (20.25 ± 0.03 mg gallic acid equivalents per gram of extract). On the other hand, the value of phenolic content was slightly decreased 19.1 ± 0.81 mg gallic acid equivalents per gram of extract for the hot water extract. It was also found that both the extracts were potentially capable of balancing reactive oxygen species. Disc diffusion assay results indicated that the extract of red alga K. alvarezi were more efficient against B. cereus. Among the fatty acids determined levoglucosenone and 4-Pyridinemethanol were present in high percentages in hot water extract whereas Hexamethyl- cyclotrisiloxane followed by 1, 2, 5- Thiadiazole-3-carboxamide, 4-[(2-chloroethyl) amino]-N-(2-hydroxyethyl) were present in ethanolic extract of K. alvarezi. The present study concluded that, hot water extracts of K. alvarezii can be used for large scale production of bioactive compounds utilizing an easily available potential seaweed. Future research of red seaweed will be highly important for pharmaceutical and medicinal field as well as a homogenizer in milk products, toothpaste and jellies in other industrial applications.

A comparison of nutritional values of Kappaphycus alvarezii, Kappaphycus striatum, and Kappaphycus spinosum from the farming sites in Gorontalo Province, Sulawesi, Indonesia

Kappaphycus is a red alga which contains carrageenan. Kappaphycus alvarezii is the most popular seaweed known as cottoni in addition to several other species, such as K. spinosum (spinosum) and K. striatum (sacol). These three species of Kappaphycus were collected from farming sites of Kappaphycus in Popayato, Pohuwato district, Province of Gorontalo, Sulawesi, Indonesia. The nutritional values of these three Kappaphycus were assessed based on the analysis on their chemical composition, including ash, lipid, crude fiber, protein, carbohydrate, vitamin C, gel strength, and mineral contents including Ca, Na, and Fe, as well as fatty acids. There were no significant differences in the nutritional values of K. alvarezii, K. striatum, and K. spinosum from farming sites of Gorontalo Province, Sulawesi. However, K. alvarezii had the highest value of carbohydrate, protein, vitamin C, and gel strength, whereas K. spinosum had the highest contents of Ca, Na, and omega-6 fatty acids. Additionally, K. striatum had the highest moisture, crude fiber, Fe, and omega-3 fatty acid. It is suggested that each Kappaphycus is a potential source of important nutrition for human and animal health.

Phenotypic and mtDNA variation in Philippine Kappaphycus cottonii (Gigartinales, Rhodophyta)

Members of the carrageenan-producing seaweeds of the genus Kappapphycus have a complicated taxonomic history particularly with regard to species identification. Many taxonomic challenges in this group have been currently addressed with the use of mtDNA sequences. The phylogenetic status and genetic diversity of one of the lesser known species, Kappaphycus cottonii, have repeatedly come into question. This study explored the genetic variation in Philippine K. cottonii using the mtDNA COI-5P gene and cox2-3 spacer sequences. The six phenotypic forms in K. cottonii did not correspond to the observed genetic variability; hinting at the greater involvement of environmental factors in determining changes to the morphology of this alga. Our results revealed that the Philippine K. cottonii has the richest number of haplotypes that have been detected, so far, for any Kappaphycus species. Our inferred phylogenetic trees suggested two lineages: a lineage, which exclusively includes K. cottonii and another lineage comprising the four known Kappaphycus species: K. alvarezii, K. inermis, K. malesianus, and K. striatus. The dichotomy supports the apparent synamorphy for each of these lineages (the strictly terete thalli, lack of protuberances, and the presence of a hyphal central core in the latter group, while the opposite of these morphologies in K. cottonii). These findings shed new light on understanding the evolutionary history of the genus. Assessing the breadth of the phenotypic and genetic variation in K. cottonii has implications for the conservation and management of the overall Kappaphycus genetic resources, especially in the Philippines.

Genetic diversity of Kappaphycus species (Gigartinales, Rhodophyta) in the Philippines

The mariculture of eucheumatoids (species of Kappaphycus and Eucheuma) in the Philippines has had a long history, dating back to the 1970s. Over this period, a number of varieties have been brought into domestication; some are now widely distributed and farmed in various regions of the country, but a significant number appear to have a more restricted distribution and are farmed only in certain areas. The taxonomy of many of these seaweed cultivars and their phylogenetic relationships still remain to be resolved at the specific and subspecific levels. In this study, two mitochondrial DNA markers, COI-5P region and cox2-3 intergenic spacer, were used to assess the genetic diversity of the farmed varieties and a few specimens collected from the wild. Analysis using haplotype networks revealed several new haplotypes for K. alvarezii, K. malesianus and K. striatus, mainly from specimens collected from eastern and southwestern regions of the Philippines. The inferred phylogenetic relationships based on both mtDNA markers resolved the identity of all the materials used in the study at the species level. We present molecular evidence that K. malesianus, in addition to K. alvarezii, K. cottonii, K. inermis, K. procrusteanus and K. striatus (and, hence, all currently recognized species of Kappaphycus) occurs in the Philippines. Collectively, these observations suggest that the Philippine archipelago has richer genetic diversity of farmed and wild Kappaphycus than do the other geographic regions, consistent with the hypothesis that the Philippines is, or is part of, the centre of Kappaphycus biodiversity in the world. These findings also reveal an untapped diversity that can potentially be exploited for improving the commercial production of these carrageenophytes.

Morphological and Molecular Studies of Undescribed &lt;i&gt;Kappaphycus&lt;/i&gt; Species

Morphological and molecular studies were carried on an undescribed species of Kappaphycus (AS 12) from Sabah, Malaysia. The species displays unique and different physical characters from Kappaphycus alvarezii , K. striatus , K. malesianus and Eucheuma denticulatum in terms of branching patterns, thalli texture and colors. The phylogenetic position of this plant was inferred by cox 2-3 spacer, intergenic transcribed spacer (ITS) region and RuBisCo spacer. Based on the results from this study, it is clear that the specimen AS 12 pointed to significant differences from K. alvarezii , K. striatus , K. malesianus and E. denticulatum as supported by both morphological and molecular analyses.

Resolving the phylogenetic affinities of Kappaphycus inermis within the genus Kappaphycus (Gigartinales, Solieriaceae) using mitochondrial and plastid markers

Although the phylogeny of the genus Kappaphycus has been the subject of a number of published studies, the phylogenetic placement of Kappaphycus inermis within the genus has remained unresolved. In this study, we sought to determine the phylogenetic affinities of K. inermis with the other congeneric species using mitochondrial (cox1 and cox2–3 spacer) and plastid (rbcL and RuBisCo spacer) markers, using specimens collected from northwestern Philippines. Morphological observations of the collected materials confirmed the presence of key morphological features that distinguish K. inermis from the other members of Kappaphycus. Molecular analyses based on the organellar genetic markers revealed that K. inermis is indeed phylogenetically distinct from K. alvarezii, K. striatus, K. cottonii and K. malesianus, a species which was recently erected based on specimens from Malaysia. The Philippine K. inermis specimens formed a sister clade to K. malesianus (also referred to as “Aring-aring” in Malaysia) in phylogenetic trees inferred from cox1, cox2–3 spacer and rbcL, but not the RuBisCo spacer whose sequence is identical in both K. inermis and K. malesianus. The analysis also revealed that specimens of unidentified Kappaphycus species collected from two other sites in the Philippines and referred to as “Aring-aring” by local farmers/traders were varieties of K. alvarezii and K. striatus.

Diversity and Distribution of Natural Populations of Eucheuma J. Agardh and Kappaphycus Doty In Nusa Tenggara Barat, Indonesia

The genera Kappaphycus Doty and Eucheuma J. Agardh are amongst the most economicallyimportant seaweeds in Indonesia. Several species of Kappaphycus and Eucheuma are cultivated in many farms in Indonesia including Nusa Tenggara Barat (NTB). However the cultivated Kappaphycus is infl uenced by environmental changes. Variation in seaweed germplasm is necessary in order to produce elite lines with required quantity. More than 10 wild specimens of Eucheum/Kappaphycus species are obtained in the NTB marine waters, including E. spinosum (green and brown), E. striatum (green and brown), Eucheuma/Kappaphycus sp-1 and Eucheuma/Kappaphycus sp-2. Distribution of the species in NTB has been mapped, showing that Lombok Island has more diverse species of Eucheuma compared to Sumbawa Island. In addition, morphological and physiological characterisation of the species have been undertaken, and it is observed that there are morphological differences in the same species obtained from different coastal zones, and thus indicating morphological plasticity of the species to different environmental conditions. (Keywords: West Nusa Tenggara, E. spinosum, E. striatum, E. edulis, E. serra, natural diversity, seaweeds)

Assessment of introduced Kappaphycus (Solieriaceae, Rhodophyta) species relationships in China with molecular markers

Due to morphological plasticity and paucity of diagnostic morphological characters, the taxonomy of Kappaphycus gets more and more confused with the expanding of commercial cultivation. In this study, the phylogenetic relationship of 13 strains of introduced Kappaphycus species in China was defined using DNA molecular markers, such as 18S rDNA, rbcL and cox2-cox3 spacer region. The resolutions obtained by three different molecular markers were compared: both cox2-cox3 spacer region and rbcL sequences are eligible in inter- species identification of Kappaphycus, whereas cox2-cox3 spacer region is more variable than rbcL sequence. There is several basepairs' discrepancy among 18S rDNA sequences, while it is 100% identical among both cox2-cox3 spacer region and rbcL sequences of the ten strains of K. alvarezii. We suppose that 18S rDNA sequence can provide more information in biogeography study of Kappaphycus than other two DNA sequences.

Harvest optimization of four Kappaphycus species from the Philippines

The booming seaweed industry in the Philippines has been recently challenged by several problems, including the degrading quality of carrageenan extracts from farmed Kappaphycus species. One emerging concern is the correctness of certain agronomic protocols, specifically the recommended duration of culture of farmed seaweeds. We determined in this study the effect of duration of culture on seaweed biomass and carrageenan quantity and quality of four commercially farmed Kappaphycus species. A mathematical formula was then employed to derive a weekly optimization index (a metric incorporating several parameters or product attributes, viz., biomass, carrageenan yield and gel strength) which was used to determine the appropriate time of harvest. The Kappaphycus species exhibited c. 300% increase in biomass within 4–7 weeks in culture (c. 150 g from an initial biomass of 50 g wet weight) and then a biomass plateau was observed. Carrageenan yield in all seaweeds fluctuated minimally (mean: 55–58%; s.d.: 2–4%), however, gel strength peaked at 8–9 weeks of culture. Highest optimization index was obtained during week 8 for Kappaphycus alvarezii var. alvarezii and week 9 for the rest of the cultured seaweeds ( Kappaphycus striatum var. sacol , Kappaphycus sp. “aring-aring” and Kappaphycus sp. “duyan”); hence, the recommended harvest times for the respective seaweeds are during these weeks of culture. As several seaweed manuals recommend other culture durations, a revision of these is appealed in order to safeguard the quality of farmed Kappaphycus species. ► Culture duration in four farmed Kappaphycus species was optimized with the aid of a mathematical formula to derive a weekly optimization index. ► Three key attributes of these seaweed resources, viz., seaweed biomass, carrageenan yield and gel strength, were incorporated in the optimization. ► Highest optimization index was obtained during the 8th and the 9th week of culture. ► Farmed Kappaphycus species are recommended to be harvested during these weeks in culture.

Marine-derived fungi from Kappaphycus alvarezii and K. striatum as potential causative agents of ice-ice disease in farmed seaweeds

Ice-ice disease in cultivated seaweeds is often associated with environmental stress and infection by pathogenic marine bacteria. No studies have associated the disease with marine fungi. Our study aimed to isolate marine fungi from cultivated Kappaphycus species and assess their ability to induce the disease. Kappaphycus alvarezii and K. striatum were collected from Calatagan, Batangas, Philippines. Following washing with sterile artificial seawater and inoculation into culture media, 18 morphospecies of marine-derived fungi (MDF) were isolated. Fungal diversity (Hss2.4) in infected seaweeds was higher than in healthy specimens. K. striatum (orange variety) had the highest incidence of MDF with 67 isolates, while K. striatum (green variety) had the lowest incidence with only 17 isolates. The ability of MDF to produce carrageenolytic and cellulolytic enzymes and utilize algal components was also tested. Of the 18 MDF selected, three had carrageenolytic activity and ten had cellulolytic activity. Most isolates utilized carrageenan, agar, and cellulose. Among the 10 MDF assayed for their ability to induce ice-ice disease, three isolates (Aspergillus ochraceus, A. terreus and Phoma sp.) induced ice-ice disease symptoms (thallus bleaching) in healthy, non-axenic cultures of K. alvarezii.

Abundance and Spread of the Invasive Red Algae, Kappaphycus spp., in Kane’ohe Bay, Hawai’i and an Experimental Assessment of Management Options

Several species of Kappaphycus were intentionally introduced into Kane’ohe Bay, Hawai’i in the 1970s. Subsequent research has demonstrated that these algae have spread rapidly throughout the bay and can be found in a variety of reef habitats overgrowing and killing corals. This study was conducted to (a) quantify Kappaphycus spp. abundance both spatially and temporally, and (b) investigate control options including manual removal and the use of biocontrol agents. Kappaphycus spp. distribution has increased in the bay over the period between surveys conducted in 1999 and 2002, with variation among reefs. The biomass of Kappaphycus spp. removed, and the amount of time required to manually remove them from the reef varied with habitat type, but in all cases amounted to at least 10 kg/m 2 requiring almost 2 person-hours to clear 1 m 2 . Re-growth of the algae following their removal was rapid at most sites, likely due to the experimentally demonstrated ability of the algae to re-grow from minute attachment points and the low palatability of the algae to native herbivorous fishes. The native sea urchin, Tripneustes gratilla, reduced the biomass of Kappaphycus spp. in small experimental enclosures and may be a useful biocontrol agent. Because Kappaphycus spp. are still spreading in Kane’ohe Bay and can overgrow over 50% cover on some reefs, we recommend that rapid management action be taken to prevent further damage and spread to other Hawaiian coral reefs.

Introduction of non-native species of Kappaphycus (Rhodophyta, Gigartinales) in subtropical waters: Comparative analysis of growth rates of Kappaphycus alvarezii and Kappaphycus striatum in vitro and in the sea in south-eastern Brazil

SUMMARY We compared the growth rates of Kappaphycus alvarezii (Doty) Doty ex P. Silva and Kappaphycus striatum (Schmitz) Doty, both, in vitro under different conditions of light and temperature, and in the sea. Temperature was the most important factor controlling the growth of both species, in vitro and in the field. In the sea there was a clear seasonal pattern in growth rate, attributed to temperature and salinity variation. The lower growth rates were registered in winter and spring, and the highest in summer and autumn months for both species. Based on growth rate in the field, and the production of viable tetraspores during the summer in Kappaphycus striatum, we conclude that is more profitable, and ecologically safer, to only continue with the introduction program of Kappaphycus alvarezii.

Introduction of non-native species of Kappaphycus (Rhodophyta, Gigartinales) in subtropical waters: Comparative analysis of growth rates of Kappaphycus alvarezii and Kappaphycus striatum in vitro and in the sea in south-eastern Brazil

Introduction of non-native species of Kappaphycus (Rhodophyta, Gigartinales) in subtropical waters: Comparative analysis of growth rates of Kappaphycus alvarezii and Kappaphycus striatum in vitro and in the sea in south-eastern Brazil