morphology

Sint Eustatius is a Caribbean island located in the north of the Lesser Antilles. The coastline west of the capital, Oranjestad Bay, is of vital importance to the island as it is here where tourism, recreation, the harbour and historical ruins are located. On the other hand, Oranjestad Bay has a heavily fluctuating beach, which is undesirable. The Public Entity of St. Eustatius is investigating the possibility of a coastal solution that could preserve and extend this beach. However, there is insufficient knowledge of the hydrodynamic processes and morphology available to design a solution. By analysing the morphological system, this study aims to advise the Public Entity of St. Eustatius on the decision for a coastal solution to create a beach in Oranjestad Bay.

A literature study was performed to obtain basic knowledge of the coastal system of Oranjestad Bay. A two-dimensional numerical Delft3D model was then developed to gain more in-depth knowledge of the wave, current and sediment patterns. The result of both findings is combined in a conceptual model, where the cause of the beach fluctuations along Oranjestad Bay was analysed. Based on the system knowledge and stakeholders’ demands and regulations, three alternatives to create a beach at Oranjestad Bay are proposed. The alternatives are qualitatively verified and evaluated with a multi-criteria analysis and cost-value ratio.

The literature review shows that Oranjestad Bay has the characteristics of a wave-dominated coast. The seasonal wave climate has a strong influence on the beach fluctuations that occur in Oranjestad Bay. The influence of tides and wind on sediment dynamics is expected to be minimal. The modelling study concluded that the wave climate can be described by three main wave conditions, namely a sea condition, a storm condition and a swell condition. The different hydrodynamic and morphodynamic characteristics of these conditions provide a reasonable simulation of the coastal processes in Oranjestad Bay. The model results give an impression of the seasonal wave climate and a net northward sediment transport capacity is found. These results are consistent with the expected coastal morphodynamics found in the literature study. The effect of a storm is less well represented in the modelling study. This limitation is caused by the modelling approach. In addition, there are some uncertainties in the model due to the lack of detailed coastal data in the nearshore. The conceptual model indicates that the coast of Oranjestad Bay may experience seasonal gradients
in alongshore sediment transport leading to beach fluctuations. From April to September, beaches are likely to erode due to net northward sediment transport. In addition, beaches erode due to periodic storm conditions that occur from June to November. It has been found that the recovery of beaches after a storm varies along Oranjestad Bay. Scubaqua beach recovers much faster than the beach at Smoke Alley. This is due to the larger sediment transport capacity in the alongshore direction at Smoke Alley beach, the amount of larger cobbles on the shoreline of Smoke Alley and the lack of sediment north of Smoke Alley...

Abstract

Resumen C. nigricolor fue considerada una especie plena, luego fue reasignada como una subespecie de C. lemnniscatus. Posteriormente fue elevada otra vez a especie plena por quienes presentaron una nueva diagnosis, basada en un trabajo comparativo entre muestras obtenidas del Archipiélago de los Roques en Venezuela (C. nigricolor)y de Surinam (C. lemniscatus). Inicialmente la distribución geográfica de C. nigricolor estaba restringida a varias islas frente a la costa norte de Venezuela, específicamente al archipiélagos de Los Roques (localidad tipo), Las Aves y Los Hermanos y las islas La Blanquilla, La Orchila y la Tortuga.Esta amplia distribución de C. nigricolor contrasta con otras especies del mismo género que están restringidas a una sola isla: Cnemidophorus arubensis (Aruba), C. murinus murinus (Curazao), C. m. ruthveni (Bonaire), C. senectus (Margarita y Cubagua), C. flavissimus (Archipiélago Los Frailes) y C. vanzo, lo cual hace suponer que dentro de C. nigricolor pueden estar incluidas varias especies crípticas. Había reportado la presencia de variación, aunque limitada, en el tamaño de las escamas braquiales y mesopigiales y en el color de los individuos de las islas venezolanas de Los Roques, Las Aves y La Blanquilla.

https://repositorioslatinoamericanos.uchile.cl/handle/2250/4949288

Chaetopteridae forms a monophyletic clade showing an uncertain position within Annelida. The family has 75 ubiquitous species within four genera that cluster in two well-supported clades (Chaetopterus–Mesochaetopterus and Spiochaetopterus–Phyllochaetopterus) and includes several cryptic species complexes. Based on integrative taxonomy and supported by citizen science, here we describe one new and two unnamed species of Caribbean chaetopterids. Partial sequences from the nuclear 18S rRNA and mitochondrial Cytochrome Oxidase I genes of all known chaetopterid genera allowed us to (1) discuss the phylogeny of the family and (2) assign the three species into Mesochaetopterus (two) and Phyllochaetopterus (one). Mesochaetopterus stinapa, sp. nov. clearly diverged from all species of the genus, whereas Mesochaetopterus aff. xerecus forms a separate clade with Mesochaetopterus rogeri (Europe) and Mesochaetopterus xerecus (Brazil). Phyllochaetopterus aff. verrilli forms a separate clade with Phyllochaetopterus arabicus (Red Sea) and the closely related sequences from Hawai’i, Australia and French Polynesia attributed to Phyllochaetopterus verrilli (or cf. verrilli). Despite observing differences in morphology (e.g. palp colour pattern, presence or absence of eyespots, chaetal morphology and arrangement) and biogeographical distributions, only the erection of M. stinapa as a new species is well supported by the genetic distance, barcoding gap and species discrimination analyses. Our results emphasise the existence of cryptic species complexes within Mesochaetopterus and Phyllochaetopterus, whose taxonomy will require further morphological, biogeographical and molecular data to be resolved.

Request full text here: https://www.publish.csiro.au/IS/IS21081

Correspondence to: dani@ceab.csic.es

This one-year pilot project aims to provide an insight in the ecology of Antigonon leptopus (Corallita) an invasive vine, which is overgrowing the native vegetation (Photo 1). This pilot project is just a first step in controlling the Antigonon leptopus. This research was done on a small scale and under controlled circumstances. Our ideas are just for small scale use in town but also to eradicate ‘hotspots’ to prevent further spreading especially near the National Parks. The government with STENAPA as a consultant should take further actions to continue this project and put it as a high priority. The first step was made and we hope this will contribute in containing the species and monitoring the species closely. More research on the life circle and possible natural enemies and its sensitivity for herbicides should be done in order to start a larger scale eradication campaign. The project does not stand on its own, the vine contributes in the prevention of soil erosion on the island. A full size project including replanting/reforestation with native species and renewed agricultural activities should be set up for the long term.

Objectives

• The primary research aim is to reduce and control the growth of Corallita on St. Eustatius and to prevent the species from invading the national parks. In order to achieve this, it is necessary.
• To gather information about the ecology of the species, such as its life cycle, dispersal, germination capacity, use of the species by animals etc. • To gather information about how the species will react on different potential control methods.
• Inform the local community about control methods if usable results are obtained.

Discussion and conclusion

Three weeks after the first treatment at Gallow Bay no regrowth was observed, this means the herbicide does work with smaller concentration (12.5% and 25%) on short term. After six weeks the first regrowth was observed. The tubers are still intact after the first treatment. It is not known how many times the treatment with these concentrations is needed.

In both plots of Sandy Road the plants have regrowth after 7½ weeks. Our observation on 13th January 2007 showed that a lot of Corallita was growing from the border into the plots covering the soil. The treatment did work but probably needed a second treatment if there is regrowth of 30-40cm. Further monitoring of large plots (during one year) is needed to make sure smaller concentrations will kill the plants. Tubers should de dug up and checked on viability. New plots should be selected.

This article describes molly's morphology in different sex, natural habitats, captive molly requirements, and feed. 

Short summary:

In 1963, there are three tooth carps species native to the islands: the molly (Poecilia sphenops), one-spot molly (P.vivipara), and guppy (P.reticulata). The local variety of P.sphenops in three islands had been described already in 1887 by van Lidth de Jeude as P. vandepolli (named for its collector, van de Poll). The vernacular name of the local is machuri. In the early 1960s, Constance Feltkamp and Ingvar Kristensen investigated the islands, and later they wrote the article "Ecology and morphological characters of different populations of Poecilia sphenops vandepolli." 

Growth of tourism, urbanization, agriculture and road construction generally cause loss of habitats for native species of all kinds. In late 2004, I went to the islands to see what possible impact these factors may have had on the distribution of the local molly, especially on Aruba, due to the growth of tourism there. I found mollies in Aruba at three locations: the wetlands in northwest, at Bringamosa, and Modanza, both close to Arikok National Park; in Curacao at two locations in Willemstad; and in Bonaire at Sorobon.

Morphometric measurements were taken from queen conch (Strombus gigas) from various sections of the Antigua and Barbuda shelf to: 1) ascertain if there were spatial variability regarding morphology; 2) analyse length-weight relationships for various maturation stages; 3) develop statistically valid conversion factors for different levels of processed conch meat; and 4) assess current management regimes (e.g., minimum size / weight). For both juvenile and adult conch, shell length differed significantly among the coastal groupings, p < 0.001. Shell lip thickness, an indicator of the age, was also significantly different among the coasts (p < 0.001), where conch from the north and west coast were significantly older than those from the east or south coast of Antigua (p < 0.001). Significant sexual dimorphism was only detected for adult conch (p < 0.001), with females being 4% larger than their male counterpart. The mean lip thickness for conch collected from commercial fishing trips was 25.0 mm (N = 785, S.D. = 5.5 mm) indicating that divers were targeting an old population however the sex ratio of the allowable catch (minimum weight of 225g) was favouring the harvesting of female conch, X2 (1, N = 711) = 4.26, p < 0.05. Conversion factors differed significantly among maturation stages (juvenile, sub adult, adult and old adult), p < 0.001; hence the use of a single conversion factor to transform processed conch to nominal weight is problematic since conversion factor is dependent on the age structure of the population. These morphological differences require a multifaceted management approach (closed season, protected areas, etc) to ensure the long-term sustainability of the fishery. 

A review of the literature and examination of over 3,200 specimens of shallow water (<200 m) tropical western Atlantic (TWA) Drilliidae Olson, 1964 in museum and private collections has resulted in the recognition of numerous previously undescribed species, 100 of which are proposed here for the first time. A total of 65 names were found in the literature. Of these, 48 are considered valid, 16 synonyms, and one nomen dubium. In addition, characteristics that distinguish each genus currently in use for TWA shallow water species have indicated the need for reassignment (new combinations within Drilliidae) of 15 species. Some nomenclatural actions have come about from the literature review and include one taxon placed in junior synonymy (under an older name recently re-discovered) and one new name for a junior homonym. Two neotypes, five lectotype designations, and one new name are also proposed. Altogether, nomenclatural actions on 17% of valid previously described taxa are proposed. The 100 proposed names are placed in 12 available and one new genus: Agladrillia Woodring, 1928 (2), Bellaspira Conrad, 1868 (7), Calliclava McLean, 1971 (3), Cerodrillia Bartsch & Rehder, 1939 (11), Clathrodrillia Dall, 1918 (6), Decoradrillia, new genus (4), Douglassia Bartsch, 1934 (4), Fenimorea Bartsch, 1934 (15), Leptadrillia Woodring, 1928 (12), Lissodrillia Bartsch & Rehder, 1939 (8), Neodrillia Bartsch, 1943 (2), Splendrillia Hedley, 1922 (13), and Syntomodrillia Woodring, 1928 (13). These are the first reports of Calliclavain the western Atlantic, previously known only from the eastern Pacific. The new genus, Decoradrillia, is proposed to hold four new species and one existing that share a unique shell microsculpture and other morphological traits. One genus, Drillia Gray, 1838, is not currently believed to have TWA representatives. Three genera comprised exclusively of bathyal species are not treated in this work: Clavus Monfort, 1810 (=Eldridgea Bartsch, 1934), Globidrillia Woodring, 1928, and Spirotropis Sars, 1878. The significant increase in species within all of the genera has the effect of strengthening the groups’ diagnostic characters by their presence across a greater number of species. Each of the 148 valid species treated herein are described (or redescribed) and photographs of types presented, as are photographs of morphological variants and representatives from separate geographic areas, if available, to illustrate species’ variability