Caulerpa Species Research Articles

Physiological and proteomic responses of Posidonia oceanica to phytotoxins of invasive Caulerpa species

The invasive green algae Caulerpa taxifolia (M. Vahl) C. Agardh, 1817 and Caulerpa cylindracea Sonder, 1845 are widely diffused in the Mediterranean Sea, where they compete for space with the endemic seagrass Posidonia oceanica (Linnaeus) Delile, 1813, a keystone species in Mediterranean marine biodiversity. The present study aims to explore the possible effects of bioactive metabolites from the invasive algae on the seagrass, which may imply an allelopathic action. In particular, the study focuses on the effects of the algal alkaloid caulerpin and the sesquiterpene caulerpenyne. Changes in leaf growth, chlorophyll content, and leaf protein expression of P. oceanica genets under treatments were evaluated after 28 days of cultivation in mesocosms. Caulerpenyne strongly inhibited the growth of adult leaves and the formation of new ones, while inducing the elongation of the intermediate leaves and increased total chlorophyll content; on the contrary, caulerpin did not significantly influence leaf growth and the formation of new ones. A total of 107 differentially accumulated proteins common to the two treatments were also identified using the proteomic approach. Both molecules induced cells to maintain homeostasis, enhancing the amino acid metabolism or fatty acid biosynthesis. Despite these disruptions, P. oceanica demonstrated a more efficient response to stress induced by caulerpin, stimulating the biosynthesis of essential amino acids to maintain cellular homeostasis and mitigate damage caused by reactive oxygen species (ROS). Overall, obtained results supports the possible role of caulerpenyne, and not caulerpin, as an effector in allelopathic interactions among invasive Caulerpa species and P. oceanica in the Mediterranean.

Cultivation of edible Caulerpa species in Malaysia: Current status and future prospects for sustainable aquaculture

Cultivation of edible Caulerpa species in Malaysia: Current status and future prospects for sustainable aquaculture

Taxonomic Insights into Caulerpa (Bryopsidales, Chlorophyta) Species in French Polynesia: Confirmation of 13 Species and Reinstatement of C. pickeringii Harvey & Bailey

Caulerpa J.V. Lamouroux is a genus of green macroalgae belonging to the family Caulerpaceae in the order Bryopsidales. The genus comprises 104 currently accepted species, of which 51 have been recorded from Pacific Islands. Among these islands, French Polynesia is found in the middle of the South Pacific Ocean and includes five archipelagos (i.e., the Austral, Gambier, Marquesas, Society, and Tuamotu Islands) where seaweed inventories have reported a total of 16 Caulerpa species so far based on morphology. Here, based on a sampling covering the five archipelagos of French Polynesia, we attempt to (i) verify the taxonomy of Caulerpa species present in these regions based on phylogeny, (ii) describe in more detail the specific diversity between the five archipelagos, and (iii) provide a morphological identification tool for these species. We successfully obtained 134 new tufA sequences for phylogenetic analyses, which corresponded to 13 species. We propose to resurrect C. pickeringii Harvey & Bailey for representatives of C. webbiana var. pickeringii and classify it in the Caulerpa subgenus Araucarioideae. We also transfer C. seuratii to C. pickeringii based on genetic results. A new morphological identification key is provided as well as an updated distribution of Caulerpa species across French Polynesia.

Physiological responses of Caulerpa spp. (with different dissolved inorganic carbon physiologies) to ocean acidification

ABSTRACT Caulerpa is a widely distributed genus of chlorophytes (green macroalgae) which are important for their dietary, social and coastal ecosystem value. Ocean acidification (OA) threatens the future of marine ecosystems, favouring macroalgal species that could benefit from increased seawater carbon dioxide (CO2) concentrations. Most macroalgae species possess CO2 concentrating mechanisms (CCMs) that allow active uptake of bicarbonate (HCO3 −). Those species without CCMs are restricted to using CO2, which is currently the least abundant species of dissolved inorganic carbon (DIC) in seawater. Thus, macroalgae without CCMs are predicted to be likely benefit from OA. Caulerpa is one of the rare few genera that have species both with and without CCMs. The two most common Caulerpa species in New Zealand are C. geminata (possesses a CCM) and C. brownii (non-CCM). We investigated the responses of growth, photo-physiology and DIC utilisation of C. geminata and C. brownii to four mean seawater pH treatments (8.03, 7.93, 7.83 and 7.63) that correspond to changes in pH driven by increases in pCO2 simulating future OA. There was a tendency for the mean growth rates for C. brownii (non-CCM) to increase under lower pH, and the growth rates of C. geminata (CCM) to decline with lower pH, although this was not statistically significant. However, this is likely because variability in growth rates also increased as seawater pH declined. There were few other differences in physiology of both species with pH, although there was tendency for greater preference for CO2 over HCO3 − uptake in the CCM species with declining seawater pH. This study demonstrates that DIC-use alone does not predict macroalgal responses to OA.

Studies on Seasonality of Marine Algae at Appikonda, Visakhapatnam District, East Coast of India

Seasonal studies on marine macro algae present along the coastal regions of Appikonda near Steel plant of Visakhapatnam was studied for a period one year during 2017 to 2018. Quadrant studies were conducted for three seasons such as winter, summer and monsoon, identified 24 macro algal forms in all three seasons of the year. Maximum number of species were recorded during winter season and minimum number of species were recorded in summer season during period of the investigation. Species of Ulva, Caulerpa, Cladophora, Chaetomorpha, Spongomorpha, Gracilaria, Gratelophia, Amphiroa, Jania, Gelidiopsis and Gelidium were present in all seasons along the intertidal habitats of the study area.

Photosynthetic, Molecular and Ultrastructural Characterization of Toxic Effects of Zinc in Caulerpa racemosa Indicate Promising Bioremediation Potentiality.

Caulerpaceae are unconventional green algae composed of multinucleated, single siphonous cells. The species of Caulerpa are acquiring major scientific interest for both their invasion in the Mediterranean ecological niche and for the production of valuable natural metabolites. Furthermore, the abilities of Caulerpa spp. in the biorecovery of polluted waters were recently investigated. Among heavy metal contaminants in marine systems, zinc (Zn) is considered a critical pollutant, progressively accumulating from plastic leachates. In this study, the responses of Caulerpa racemosa to different levels (5-10 mg L-1) of Zn were studied for 14 days under laboratory-controlled conditions. Effects of Zn were monitored by measuring the growth rate, photosynthetic efficiency and gene expression. Moreover, the ability of Caulerpa to remove Zn from seawater was monitored. Zn induced detrimental effects by decreasing the relative growth rate (RGR) and maximal PSII photochemical efficiency (Fv/Fm). Moreover, C. racemosa, grown in contaminated seawater, reduced the levels of Zn to a final concentration of 1.026 and 1.932 mg L-1 after 14 days, thus demonstrating efficient uptake. Therefore, our results characterized the effects of zinc on C. racemosa and the possible role of this alga as being effective in the bioremediation of marine seawater.

DIVERSITY AND ABUNDANCE OF GREEN SEAWEED Caulerpa (Chlorophyta) ACROSS INDONESIAN COASTAL WATERS WITH DIFFERENT NUTRIENT LEVELS: Bintan Island, Jepara, and Osi Island

The green seaweed Caulerpa can be found in almost every coastal area of Indonesia, and it is one of the seaweeds with immense potential to be developed in the future. The chemical factors, especially water nutrients (nitrate, nitrite, phosphate, and ammonia), play an essential role in the distribution and diversity of seaweed. This study aimed to identify the abundance, ecological index, and relationship between the water column nutrients concentration and the biodiversity of Caulerpa from three different locations (Bintan Island, Jepara, and Osi Island). There were 12 points of observation at each site. The result showed a correlation between the nutrient levels and the abundance and diversity of Caulerpa in three locations. The nitrate, ammonia, and DIN:P ratio values were significantly different between areas. In contrast, there were insignificant differences in nitrite and phosphate concentrations between sites. The highest nitrate and phosphate concentrations were observed on Osi Island. The nitrite and ammonia values were identical for the condition on Bintan Island. The nitrate value was the main characteristic that distinguished the water nutrient at all sites. The Caulerpa species found in this research were Caulerpa racemosa, Caulerpa lentilifera, Caulerpa serrulata, Caulerpa sertularoides, and Caulerpa cupresoides. The nitrate and phosphate values influenced the growth factor of the green seaweed Caulerpa lentilifera. Caulerpa racemosa and Caulerpa serrulata, on the other hand, grew in response to ammonia levels. Caulerpa cupresoides diversity and abundance were impacted by the nitrite value. The results of the canonical correspondence analysis revealed that nitrate, phosphate, and ammonia were the most important factors influencing Caulerpa distribution in three locations.

Phytochemical Analysis and Molecular Identification of Green Macroalgae Caulerpa spp. from Bali, Indonesia.

The studies of the Bulung Boni and Bulung Anggur (Caulerpa spp.) species and secondary metabolites are still very limited. Proper identification will support various aspects, such as cultivation, utilization, and economic interests. Moreover, understanding the secondary metabolites will assist in developing algae-based products. This study aimed to identify these indigenous Caulerpa algae and analyze their bioactive components. The tufA sequence was employed as a molecular marker in DNA barcoding, and its bioactive components were identified using the GC-MS method. The phylogenetic tree was generated in MEGA 11 using the maximum likelihood method, and the robustness of the tree was evaluated using bootstrapping with 1000 replicates. This study revealed that Bulung Boni is strongly connected to Caulerpa cylindracea. However, Bulung Anggur shows no close relationship to other Caulerpa species. GC-MS analysis of ethanolic extracts of Bulung Boni and Bulung Anggur showed the presence of 11 and 13 compounds, respectively. The majority of the compounds found in these algae have been shown to possess biological properties, such as antioxidant, antibacterial, anticancer, anti-inflammation, and antidiabetic. Further study is necessary to compare the data obtained using different molecular markers in DNA barcoding, and to elucidate other undisclosed compounds in these Caulerpa algae.

First records of the non-indigenous green algal species Siphonocladus tropicus (Cladophorales, Chlorophyta) and Caulerpa integerrima (Bryopsidales, Chlorophyta) in the Mediterranean Sea

ABSTRACT We provide an account of two newly recorded non-indigenous tropical seaweed species, Siphonocladus tropicus (Cladophorales, Chlorophyta) and Caulerpa integerrima (Caulerpaceae, Chlorophyta), from the northern and central Levantine Mediterranean shores of Israel. Reports are supported by morphological and molecular evidence. The new record of C. integerrima, thought to be endemic to the Red Sea, increases the number of non-indigenous Caulerpa species in the Mediterranean Sea to eight. Siphonocladus tropicus, a widespread tropical species, is also being reported from the northern Red Sea. Furthermore, morphological comparison of populations from the northern Red Sea and the Levantine Mediterranean shore of Israel revealed that there might be a regional variant or form of this species in the northern Red Sea and might indicate that this new invader does not necessarily originate from the Red Sea. The increasingly tropical conditions in the eastern Levantine Sea as a result of global warming probably paved the way for the establishment of both species in the region. Aspects of the new invaders’ ecology in the Israeli Levantine Sea, the possible vectors of introduction and origins, as well as the status of other Caulerpa species from both Levantine and Red Sea shores, are discussed. HIGHLIGHTS Siphonocladus tropicus and Caulerpa integerrima are new non-native species found lately in the Mediterranean Sea. Caulerpa integerrima originated from the Red Sea whereas the origin of Siphonocladus tropicus is uncertain. The introduction of these two alien species, especially Caulerpa integerrima, might pose a threat to the local marine flora and fauna.

Bio-prospection and compositional multivariate analysis revealed the industrial potential of selected seaweeds along Gujarat seacoast

Seaweeds are important marine resources and over-exploited for different applications. The study reports on biochemical constituents and multivariate analysis of abundantly available seaweeds along Gujarat seacoasts. The green seaweeds contained highest galactose contents and found rich in chlorophyll pigment, mineral and protein (12.98 ± 0.49 mg g−1 dw) contents. Brown seaweeds contained highest glucose contents along with carotenoids, fucoxanthin and minerals. Lipids (62.67 ± 0.67 mg g−1) in brown seaweeds constituted higher SFA and MUFA. Red seaweeds contained higher contents of galactose and phycobilin pigments and PUFA. The multivariate analysis enlightened the chemosystematics and biochemical mapping of seaweeds. Novelty of the work suggested cultivation of rhodophyta for pigments and phaeophyta for fatty acid production. The Caulerpa species can serve as biomass resource for biofuel production and Ulva species for production of a protein-rich diet. The results would benchmark the potential seaweed feedstock along Gujarat seacoast for seaweed bio-refinery development.

Molecular Identification, Nutritional Profile and Heavy Metals Content of Edible Caulerpa from Binuangeun Coast, Banten

Two species of Caulerpa, locally known as “Pedesan” and “Latuh” have been traditionally consumed by coastal communities at Binuangeun, Banten. This study aimed to identify “Pedesan” and “Latuh” using the DNA barcoding method and to evaluate their nutrient and heavy metal contents. Fatty acids were determined by Gas Chromatography Flame Ionization Detector (GC FID), amino acids using Ultra Performance Liquid Chromatography (UPLC), and minerals using Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). Based on the tufA gene sequences, the “Pedesan” was identified as Caulerpa racemosa var. macrophysa and “Latuh” as Caulerpa chemnitzia. Thirteen fatty acids were detected in C. racemosa var. macrophysa and twelve fatty acids in C. chemnitzia. Of the total fatty acid content, C. racemosa var. macrophysa contained 41.0% unsaturated fatty acids, dominated by linolenic acid and eicosapentaenoic acid. Meanwhile, C. chemnitzia contained 47.5%, dominated by oleic acid. Both seaweeds contained fatty acids with the w6/w3 ratio lower than 10, which could prevent heart disease risk based on World Health Organization (WHO) recommendation. The primary amino acids content in C. racemosa var. macrophysa were glutamic acid, alanine, serine and aspartic acid, while those in C. chemnitzia were glutamic acid, serine, aspartic acid, and glycine. The high content of glutamic acid in both samples indicated their potential use as food flavor enhancer. The Na/K ratio of C. racemosa var. macrophysa (40.31) and C. chemnitzia (27.48) were higher than those recommended by WHO. Heavy metals were not detected in either “Pedesan” nor “Latuh”, indicating that they are safe for consumption.

Comparative evaluation of multiple protein extraction procedures from three species of the genus Caulerpa

The aim of this study was to define the simplest and least expensive protocol for total protein extraction for three different macroalgae of the genus Caulerpa (the invasive C. taxifolia and C. cylindracea and the autochthonous C. prolifera). Five multi-step protein extraction procedures, set up for other macroalgal species, were tested. For each of them, different pre-treatment and extraction conditions were simultaneously examined, according to a factorial design, considering the starting material, the solvent-to-biomass ratio, and the incubation temperature. Protein yield in the obtained extracts was estimated with the Bradford method. Further, polyacrylamide gel electrophoresis (SDS-PAGE) was used to resolve proteins, assessing their quality and integrity. Significant differences in protein yield were observed among the extraction protocols and the conditions tested, also in relation to the considered species. Profiles having an acceptable quality were obtained for C. prolifera and C. cylindracea, and from the obtained results, the best method to obtain high yield and quality protein extracts for the two above-mentioned species appears to require the use of a primary TCA/acetone extraction buffer followed by a lysis buffer with NaCl, KCl, urea, Triton, SDS and a protease inhibitor. The best results, in particular, were obtained starting from fresh pulped material with a buffer-to-biomass ratio of 10:1 and an incubation temperature of 4°C. For C. taxifolia, instead, none of the tested protocols produced satisfactory results and further studies will be required.

STUDY OF POPULATION DYNAMICS AND EXPLOITATION RATES OF CRAYFISH (PANULIRUS SPP) IN SPERMONDE WATERS, MAKASSAR STRAIT

To stimulate catch production and wise management patterns, research is carried out on the study of ecological aspects, estimates of population dynamics and exploitation rates of crayfish (Panulirus Spp) in the Spermonde waters of the Makassar Strait. Based on the COA (Correspondence Analysis) (Ludwig and Reynold, 1988), as well as the analysis of Von Bertalanffy (1938, in Sparre et al., 1989), it was found that the micro-habitat of Panulirus spp., Generally co-exist with massive coral species Alcyonaria (Sarcophyton, Heliophora , and Tubipora), and branching reefs of the Acropora species (Goniopora and Pavona), as well as living with algal grass species of Caulerpa and Halimeda. The growth pattern of Panulirus lobster follows the equation Lt = 46.3561 (1- e -0.1738 (t + 1.7827)), which means that the length decreases at relatively old age. The total mortality coefficient (Z) of population is 0.5066/year, this is relatively the same as the ideal mortality (M) which means optimal utilization, but it is necessary to select catch sizes that are larger than 24 - 27cm (in the range of 34 - 46cm).

Caulerpa wysorii sp. nov., a denuded Caulerpa (Chlorophyta) resembling C. sertularioides when ‘dressed’

ABSTRACT Routine DNA barcoding with the chloroplast gene tufA identified novel records of an unknown and denuded (i.e. lacking branchlets) Caulerpa species previously reported from the Florida Middle Grounds. tufA barcoding not only confirmed the matching molecular identity of this taxon with several newly collected denuded specimens from shallow habitats of the Yucatán shelf, but also with a set of plumose specimens previously collected from mesophotic depths of the West Florida shelf and recorded as Caulerpa sertularioides. Sequencing of two additional, faster-evolving DNA markers, i.e. nuclear ITS and the newly tested chloroplast-encoded rpoA, each confirmed conspecificity of the above morphotypes and the molecular separation of the new taxon from C. sertularioides and filiform species found in the region, namely C. cupressoides f. denudata and C. fastigiata. In light of our sequencing results and review of the early taxonomic history of filiform Caulerpa, we propose the description of Caulerpa wysorii sp. nov. for this new species that exhibits two distinct morphotypes in currently available collections, i.e. filiform or plumose assimilators. We also subsume C. tongaensis within the broadly distributed C. fastigiata, whose lectotype is also designated herein. In addition to Caulerpa wysorii sp. nov., we discovered yet another unknown denuded species from the Campeche Banks represented by a single specimen thus far.

MINERAL CONTENT AND PHYTOCHEMICAL PROPERTIES OF SELECTED CAULERPA SPECIES FROM MALAYSIA

Seaweeds are abundant and are an important renewable resource for the coastal community since they are rich sources of minerals and natural bioactive compounds. Among them, the Caulerpa species under green seaweeds is widely consumed by locals in Southeast Asia. Edible seaweeds are often associated with various health benefits. However, in Malaysia, limited studies have been done on the mineral and antioxidant levels of seaweeds, especially for the Caulerpa species. Thus, the present study aimed to evaluate the variations of minerals and antioxidants of selected Caulerpa species in Malaysia. The samples were collected in two study sites, which were Blue Lagoon, Port Dickson and Merambong Shoal, Johor. Two species, C. racemosa and C. manorensis were recorded from Merambong Shoal, Johor, while five species were recorded namely C. sertularioides, C. racemosa var lamourouxii, C. lentillifera, C. racemosa var cylindracea and C. racemosa at Blue Lagoon, Port Dickson. Among all the Caulerpa species from both study sites, C. manorensis possessed the highest phosphorus content (139.54 mg/100g) while C. racemosa from both Merambong and Blue Lagoon Port Dickson’s calcium (Ca) content was significantly highest at 2318.33 – 2406.66 mg/100g. All the Caulerpa species possessed high sodium (Na) content ranging 9338.30 – 21748.30 mg/100g. For micronutrients, the highest zinc content was recorded in C. manorensis (3.40 mg/100g) while the copper content was significantly highest in C. racemosa from Port Dickson (1.05 mg/100g). The methanol extract of C. sertularioides possessed phytochemical attributes of high antioxidant activity (DPPH EC50 = 24.16 mg/mL) with a high FRAP value being recorded in C. lentillifera (27.09 mg TE/100g). The TPC and TFC were highest in C. lentillifera with 57.95 mg GAE/100g and 1506.41 mg QE/100g respectively. The present study revealed that Caulerpa species contained constituents with significant mineral compositions and phytochemical attributes suitable for pharmaceutical and nutraceutical uses.  

Bioinformatic Characterization of Sulfotransferase Provides New Insights for the Exploitation of Sulfated Polysaccharides in Caulerpa.

Caulerpa is an unusual algal genus from Caulerpaceae (Chlorophyta, Bryopsidales). Species from this family produce a wide range of metabolites suitable for biotechnology applications. Among these, sulfated polysaccharides (SPs) are often highly desirable for pharmaceutical and nutraceutical applications. Here, we provide a classification of sulfotransferases from Caulerpa; these important enzymes catalyze the nodal step for the biosynthesis of SPs. For this, we performed phylogenetic, genomic, expression analyses and prediction of the protein structure on sulfotransferases from Caulerpa. Sequences, domains and structures of sulfotransferases generally shared common characteristics with other plants and algae. However, we found an extensive duplication of sulfotransferase gene family, which is unique among the green algae. Expression analysis revealed specific transcript abundance in the pinnae and rachis of the alga. The unique genomic features could be utilized for the production of complex SPs, which require multiple and specific sulfation reactions. The expansion of this gene family in Caulerpaceae would have resulted in a number of proteins characterizing the unique SPs found in these algae. We provide a putative biosynthetic pathway of SPs, indicating the unique characteristics of this pathway in Caulerpa species. These data may help in the future selection of Caulerpa species for both commercial applications and genetic studies to improve the synthesis of valuable products from Caulerpa.

The Ulvophyceae (Chlorophyta) of eastern Sorsogon, Philippines, including Halimeda magnicuneata sp. nov. (Bryopsidales)

Abstract The marine algal flora of eastern Sorsogon has been intensively collected and is generally considered as the richest in the Philippines. A trend of species records in the area has been dominated by rhodophytes (red algae) with significantly fewer similar studies for other algal groups (green and brown algae). In this study we present an updated catalogue of the green seaweeds (Ulvophyceae) of eastern Sorsogon. A checklist, including notes on taxonomy, is given of the 103 species. Twenty-six species are newly recorded locally of which five represent new records for the Philippines: Avrainvillea amadelpha, Caulerpa buginensis, an unidentified Caulerpa species, Codium cf. latum, and one taxon new to science. The new species is described as Halimeda magnicuneata Verbruggen et Dumilag based on morpho-anatomy and DNA sequence data. The number of ulvophycean species recorded in eastern Sorsogon is found to be the highest in the Philippines. This may be a result of the high collection effort in the region, as well as eastern Sorsogon’s diverse habitats providing favourable conditions for a wide range of seaweed species.

Morphological variation of two common sea grapes (Caulerpa lentillifera and Caulerpa racemosa) from selected regions in the Philippines

Abstract. Estrada JL, Bautista NS, Dionisio-Sese ML. 2020. Morphological variation of two common sea grapes (Caulerpa lentillifera and Caulerpa racemosa) from selected regions in the Philippines. Biodiversitas 21: 1823-1832. Seagrapes, locally known in the Philippines as “lato” or “ar-arusip”, are economically important macroalgae belonging to the edible species of the genus Caulerpa. This study characterized and compared distinct populations of sea grapes from selected regions in the Philippines and described the influence of physicochemical parameters of seawater on their morphology. Morphometric, cluster and principal component analyses showed that morphological plasticity exists in sea grapes species (Caulerpa lentillifera and Caulerpa racemosa) found in different sites in the Philippines. These are evident in morphometric parameters namely, assimilator height, space between assimilators, ramulus diameter and number of rhizoids on stolon wherein significant differences were found. This evident morphological plasticity was analyzed in relation to physicochemical parameters of the seawater. Assimilator height of C. racemosa is significantly associated and highly influenced by water depth, salinity, temperature and dissolved oxygen whereas for C. lentillifera depth and salinity are the significant influencing factors. Highest assimilator height of sea grapes was found in Coron and Culion in Palawan due to higher salinity and temperature while in Mactan, Cebu, it is primarily attributed to lower depth and higher salinity values.

Secondary metabolites of some varieties of Caulerpa species

Several species of Caulerpa have been investigated and bioactive principles, such as caulerpin and caulerpicine have been isolated from a number of them. Caulerpin produces mild anesthetic action, difficulty in breathing, sedation, and loss of balance. The toxic syndrome has been reported to be somewhat similar to that produced by ciguatera fish poisoning. The neurotrophic activity of caulerpicine is thought to be of clinical value. Tropical green algae and a few of their temperate relatives have yielded a number of bioactive metabolites and some of these are believed to be used by the algae as a chemical defense against herbivorous animals. This research was aimed to determine the secondary metabolites compound of some varieties of Caulerpa species. Chromatography and Spectrophotometric methods were used to conduct this research. The result shows that Caulerpin and caulerpicin presence on five species of Caulerpa species Caulerpa racemosa Siquijor, Caulerpa lentillifera wild and farm from Mactan, Caulerpa clavifera Mactan and Caulerpa lentillifera cultured in the common garden. Higher absorbance of both compounds caulerpin and caulerpicin found in wild Caulerpa lentillifera from Mactan while the lowest absorbance of caulerpin found in Caulerpa racemosa collected from Siquijor, whereas the lowest absorbance of caulerpicin found in the cultured Caulerpa lentillifera in the common garden.

Molecular authentication of green algae Caulerpa (Caulerpales, Chlorophyta) based on ITS and tufA genes from Andaman Islands, India

Indigenous and non-indigenous invasive algal species introduction or prevalence is one of the major concerns to protect the native coastal environment. Globally, several studies have reported the effect of invasive alga Caulerpa on coral reefs. To establish the genetic variation between indigenous and non-indigenous invasive species, attempts have been made to develop molecular identification of Caulerpa algal species available at the Andaman Islands. In this study, 7 visually and morphologically different species belonging to the genus Caulerpa (Chlorophyta) were collected from the intertidal regions of South and Little Andaman Islands, India. The specimens were preliminarily identified based on the morphological characters and genetically mapped using ITS2 and chloroplast tuf A gene markers. Six species of the Caulerpa viz. Caulerpa racemosa , C. racemosa var lamourouxii , C. racemosa var macrophysa , C. serrulata , C. fergusonii and C. microphysa were identified using ITS2 gene, and. C. mexicana var pluriseriata was identified using tuf A gene. Two varieties, C. mexicana var. pluriseriata and C. racemosa var lamourouxii were found to be invasive to Indian waters. These were earlier reported in Red sea and in Phillipine waters in the pacific ocean. Further studies are needed to elucidate the genetic divergence of the Caulerpa species present in Andaman waters using different molecular markers.