Red Morphotypes Research Articles

A Comparative Analysis of the Venom System between Two Morphotypes of the Sea Anemone Actinia equina.

The current study investigates the venom-delivery system of green and red morphotypes of the sea anemone Actinia equina to disclose its potential as a source of bioactive compounds. We compared the two morphotypes using electron and optical microscopy, proteomics, and toxicity assessment on zebrafish embryos. Specialized venom-injecting cells (nematocysts) are equally distributed and found in the tentacles of both varieties. Proteomics revealed proteins of interest in both red and green Actinia, yielding the three most abundant Gene Ontology (GO) terms related to the biological processes "proteolysis", "hemolysis in another organism" and "lipid catabolic process". Neurotoxins and cytolytic toxins similar to known cnidarian toxins like PsTX-60A and AvTX-60A, for instance, were identified in both types. Extracts from green and red anemones were toxic to zebrafish embryos, with green anemone venom appearing to be more potent. The findings highlight the presence of proteinaceous toxins in A. equina and the potential for different varieties to possess distinct bioactive compounds. Notably, pore-forming toxins are suggested for molecular probes and immunotoxins, making them valuable assets for potential biotechnological and biomedical purposes.

First Ecological Characterization of Whip Black Coral Assemblages (Hexacorallia: Antipatharia) in the Easter Island Ecoregion, Southeastern Pacific

One of the main priorities of marine scientific research is to provide practical information and guidance for biodiversity conservation and management. In this context, the identification of key and fragile habitat-forming species is particularly important. Despite their ecological importance, whip corals in the order Antipatharia remain poorly studied around the world, and especially in the South Pacific. During recent expeditions to explore mesophotic and deep benthic habitats around Rapa Nui (Easter Island), dense assemblages of whip black corals were observed in situ. We here report the first detailed description of the distribution and abundance of these black coral assemblages and their associated fauna and habitat. These descriptions were based on analysis of video surveys collected on 67 remotely operated vehicle dives conducted in 2014 through 2019 at three sites (Pukao seamount, Apolo peak, and Rapa Nui Island shelf and slope) within the Easter Island Ecoregion at depths between 50 and 330 m. At least four morphotypes (yellow, red, white/orange, and Pukao) of unbranched black corals were detected. Each morphotype had polyps arranged in a single row on only one side of the corallum, a diagnostic morphological character currently assigned to the antipatharian genus Stichopathes. Samples of the yellow and red morphotypes were collected and studied using morphological and molecular techniques. These analyses indicate that the genus Stichopathes is not monophyletic and requires further revisions, a conclusion that is consistent with previous studies. Extensive fields of whip black corals, primarily of the yellow and red morphotype, were present at 28 sites from 60 to 245 m on rocky substrates, coarse sand, or rhodoliths. Densities of these assemblages per frame were up to 58.2 ± 5.2 colonies m–2 (average: 13.2 ± 0.8), which represent some of the highest reported densities for black corals to date. Numerous faunal groups, including ophiuroids, echinoids, and fishes, were associated with these whip black coral assemblages. Our observations should be considered in future management and conservation efforts around Rapa Nui, where a multi-use marine protected area was established in 2018, as well as in adjacent international waters that remain unprotected but likely harbor similar assemblages.

Effects of climate variability on an estuarine green crab Carcinus maenas population

The increase in frequency and intensity of extreme climate events over the last few decades has been leading to profound changes in estuarine and marine ecosystems worldwide, with strong implications for the species inhabiting these ecosystems as well as for the services provided by them. In this study, we analysed the effects of climate variability on the temporal and spatial variations in population dynamics of the green crab Carcinus maenas in the Mondego estuary (Portugal), between 2003 and 2018. In this 15-year period, a greater recruitment of C. maenas was observed during drought periods, periods which was matched by an increase in secondary production. Ontogenic stage segregation was also observed, with juveniles being found mainly in the further upriver areas of the estuary. The estuarine population was mainly composed of the green morphotype, with the orange and red morphotypes present in more downstream areas of the estuary. Redundancy analysis (RDA) showed high spatial and temporal variability of C. maenas in the estuary which was related with environmental changes over the 15-year period. A correlation between C. maenas biological features and several local-scale (salinity and river runoff) and large-scale (North Atlantic Oscillation index and Eastern Atlantic pattern) environmental variables was identified through cumulative sums analysis (CUSUM), indicating a strong environmental control on C. maenas population dynamics. This paper shows the importance of relatively long-term datasets to unravel the effects of extreme weather events due to climate change on key epibenthic estuarine species, and also how they might cope with a changing marine environment.

In vitro anthelmintic efficacy of essential oils in the control of Neoechinorhynchus buttnerae, an endoparasite of Colossoma macropomum

ABSTRACT In this study, we evaluated the chemical composition and the in vitro anthelmintic efficacy of the essential oils (EOs) of the plants Aloysia triphylla, Adenocalymna alliaceum, Allium sativum, Croton cajucara (white and red morphotypes), Curcuma longa, Lippia gracilis, Lippia origanoides, Ocimum gratissimum, Mentha arvensis, and Piper aduncum against the Acantocephalan Neoechinorhynchus buttnerae. The in vitro viability of worms was observed after 24 h-exposure to nine concentrations of EOs from each plant. Lower EC50 values were obtained for M. arvensis, L. origanoides, L. gracilis, C. cajucara (red and white morphotypes), O. gratissimum, and P. aduncum. All EOs showed 100% anthelmintic efficacy in vitro in 24 h. In regard to damage to the integument of helminths, edema in the lacunar spaces with formation of bubbles in the subcuticle, body swelling, increased volume of the pseudocelomatic cavity and degeneration of the reproductive organs were observed after exposure to A. triphylla OE.

Genetic structure among morphotypes of the endangered Brazilian palm Euterpe edulis Mart (Arecaceae).

Euterpe edulis (Arecaceae) Mart has high ecological and economic importance providing food resources for more than 58 species of birds and 20 species of mammals, including humans. E. edulis is the second most exploited nontimber product from Brazilian Atlantic Forest. Due to overexploitation and destruction of habitats, E. edulis is threatened by extinction. Euterpe edulis populations have large morphological variations, with individuals having green, red, or yellow leaf sheath. However, no study has related phenotypic distinctions between populations and their levels of genetic structure. Thus, this study aimed to evaluate the diversity and genetic structure of different E. edulis morphotypes. We sampled 250 adult individuals in eight populations with the different morphotypes. Using 14 microsatellite markers, we access genetic diversity through population genetic parameters calculated in the GenAlex program and the diveRsity package in R. We used the Wilcoxon test to verify population bottlenecks and the genetic distance of Nei and Bayesian analysis for genetic clusters. The eight populations showed low allele richness, low observed heterozygosity, and high inbreeding values (f). In addition, six of the eight populations experienced genetic bottlenecks, which would partly explain the low genetic diversity in populations. Cluster analysis identified two clusters (K = 2), with green morphotype genetically distinguishing from yellow and red morphotypes. Thus, we show, for the first time, a strong genetic structure among E. edulis morphotypes even for geographically close populations.

Chemical composition of the leaf oils from two morphotypes of Psidium cattleyanum at four phenological stages

The chemical composition of volatile oil extracted from leaves of two morphotypes of Psidium cattleyanum Sabine from southern Brazil was evaluated at four phenological stages. In addition, plant material was evaluated at four different locations of the Planalto Serrano Region of Santa Catarina state, Brazil. Major components found were: 1,8-cineole, α-pinene, α-eudesmol, (E)-caryophyllene and p-cymene in red morphotype whereas 1,8-cineole, α-pinene, myrcene, (E)-caryophyllene and valerianol were found in the yellow morphotype. The differences observed in the chemical composition in red and yellow morphotypes may help in the differentiation between the two morphotypes in the absence of fruits. Also, important differences were observed mainly for 1,8-cineole and α-pinene percentage at different phenological stages.

Spatial Abundance and Colour Morphotype Densities of the Rock-Boring Sea Urchin (Echinometra lucunter) at Two Different Habitats

The rock-boring sea urchin Echinometra lucunter is a common echinoderm found throughout the intertidal zone along the northeastern coast of, Toco, Trinidad. Sea urchin abundance, size distribution, and colour morphotypes at two sites: Pequelle Bay (SB) and Grande L’Anse (GA) were quantified using 1 m2 quadrats, accessible during extreme low tides, and in two environments, notably low and high wave action. Percent coverage of cnidarian and macroalgae were estimated in each quadrat. Sea urchin densities were 9.9–17.8 urchins/m2 in high wave action, and 25.2–60.7 urchins/m2 in low wave action environments. Size (measured as maximum sea urchin diameter) are highest between 21 and 50 mm for both black and red colour morphotypes. Black colour morphs were significantly larger than red morphs (ANOVA, F2, 175 = 5.55, p < 0.05). Sea urchins at low energy environments were significantly larger than those found in high energy environments for all years (p < 0.05). Mean hard coral, soft coral, and macroalgae cover did not show any relationship with habitat type or urchin densities. Although sea urchin abundance and distribution were variable, larger urchins were more likely to be found in low wave action environments, and smaller urchins were mostly found in the open, and exposed to high wave action.

Sexual dimorphism in Sebastes owstoni (Scorpaenidae) from the Sea of Japan

Morphological and genetic differences between red and yellow morphotypes of Sebastes owstoni were investigated, utilizing 277 males [84.0–194.3 mm in standard length (SL)] and 542 females (92.3–251.5 mm SL) from the Sea of Japan. All males smaller than 120 mm SL were characterized by red body color. The frequency of specimens with yellow body color thereafter increased gradually with SL, all specimens larger than 170 mm SL being yellow. The specimens with yellow body color were observed throughout the year. All females smaller than 170 mm SL were characterized by red body color, the frequency of specimens with yellow body color tending to slightly increase with SL. However, most females had red body color, except for 16 specimens (177.7–241.5 mm SL) that were yellow, growth-related color change from red to yellow being uncommon. Morphological analysis of 49 males (107.6–193.3 mm SL) and 68 females (108.7–241.5 mm SL) showed the head length, orbit diameter, lower jaw length, and predorsal length to be relatively greater, but the distance between the pelvic and anal fins less, in males. A discriminant analysis using Mahalanobis distances resulted in 100% correct assignment of specimens to sex, regardless of SL and body color. In addition, no genetic differences were apparent between red and yellow individuals in mitochondrial DNA sequence analyses from the threonine tRNA to the first half of the control region (498 bp). Accordingly, the differences in body color, maximum size, and the five morphometric characters listed above were considered to represent sexual dimorphism. That evidenced by body color was considered to appear after that shown by morphometric characters, some exceptions in the former occurring in females. This is the first report of permanent sexual dimorphism in body color in Sebastes.