Stegastes leucostictus is a species of damselfish found near the sea bed in shallow waters on the western fringes of the Atlantic Ocean. It is known as the beau gregory or beaugregory. Stegastes leucostictus is a deep-bodied, laterally compressed bony fish, grows to about 10 cm long, it is rather variable in colour, but is dark blue or brown along the top of the head and the ridge of the back and yellowish on the flanks. The large dorsal fin has 13 to 16 soft rays; the anal fin has 12 to 14 soft rays. The caudal fin has a shallow fork and the paired pectoral and pelvic fins have no spines; the mouth is set at the tip of the snout. A juvenile S. leucostictus has blue stripes and spots on its head and a dull blue sheen on the top of the head and the upper part of the front half of the body. It has a large, black eye-spot ringed in blue, centered where the dorsal fin spines join the soft rays; as the juvenile develops, this spot moves upwards onto the fin. A dark spot just above each pectoral fin distinguishes this species from others in the genus.
Stegastes leucostictus is found in shallow waters at depths down to about 10 m in the western Atlantic Ocean. Its range extends from the Gulf of Mexico south to Brazil, it is a demersal fish remaining within 50 cm of the seabed. Its favoured habitats are seagrass meadows, rocky or coral reefs and sandy flats and it is sometimes found amongst mangroves. Stegastes leucostictus feeds on seaweed, but consumes marine worms, amphipods and gastropod molluscs. A male damselfish guards a territory, but interacts with its neighbours, although it will attack a male of the same species introduced in a bottle placed in its territory. Dominance is related to the quality of the territory; the owner of a high-quality territory exhibits dominance and if it is removed and a subservient male moves in, it in turn develops dominance. During the breeding season, a male and a female form a pair bond; the eggs are hidden inside an empty shell or under a stone, the male guards the nest and fans the eggs with its fins to keep them well oxygenated.
The wrasse, Thalassoma bifasciatum, preys upon the eggs of S. leucostictus. A male damselfish can evaluate the level of the threat posed by one or more wrasse and react appropriately, it either chases the other fish, harries it, or adopts a head-lowered, threatening posture
Chromis cyanea is a damselfish in the subfamily Pomacentrinae, found in Bermuda, southern Florida and the Caribbean Sea. Being a shallow water fish, the blue chromis is found at depths of 3 to 5 m, but it can reach depths of 25 m below sea level. It's been recorded at a depth of 60 m below sea level, it lives on the surface of reefs, but swims in the water columns above the reefs to feed on plankton. It's a rather solitary species, seen alone or in small groups, tends to stay close to the reefs; the younger fish stay near the bottom. The males maintain a solitary breeding territory. After breeding with multiple females, they guard the eggs until the planktonic larvae hatch; the blue chromis is collected for use in aquariums. There are no reliable numbers on the extent of this collecting, but damselfish make up the most intensely collected fish group, making up half of the aquarium trade. Besides the intense aquarium trade, the rapid expansion of lionfish in the Caribbean and the Atlantic coast is the greatest threat to the blue chromis, as well as several other tropical fish native to the Caribbean.
Furthermore, the loss of live corals could have a definite impact on the species, though this has yet to be investigated more closely. The blue chromis is assessed as "Least Concern" by the IUCN. Despite appearing only within an area of 2,500,000 km2, it is considered abundant within that area, without any known continuous decline in range or population numbers. It's collected for the aquarium trade, but not in great numbers. Despite this, a deeper study is required to measure the impact of the decline in habitat quality in the Caribbean has on the species
A cenote is a natural pit, or sinkhole, resulting from the collapse of limestone bedrock that exposes groundwater underneath. Associated with the Yucatán Peninsula of Mexico, cenotes were sometimes used by the ancient Maya for sacrificial offerings; the term derives from a word used by the low-land Yucatec Maya—ts'onot—to refer to any location with accessible groundwater. Cenotes are common geological forms in low latitude regions on islands and platforms with young post-Paleozoic limestones that have little soil development. Cenotes are surface connections to subterranean water bodies. While the best-known cenotes are large open water pools measuring tens of meters in diameter, such as those at Chichén Itzá in Mexico, the greatest number of cenotes are smaller sheltered sites and do not have any surface exposed water. There are over 6000 different cenotes in the Yucatan Peninsula in Mexico alone; the term cenote has been used to describe similar karst features in other countries such as Cuba and Australia, in addition to the more generic term of sinkholes.
Cenote water is very clear, as the water comes from rain water filtering through the ground, therefore contains little suspended particulate matter. The groundwater flow rate within a cenote may be slow. In many cases, cenotes are areas where sections of cave roof have collapsed revealing an underlying cave system, the water flow rates may be much faster: up to 10 kilometers per day. Cenotes around the world attract cavern and cave divers who have documented extensive flooded cave systems through them, some of which have been explored for lengths of 340 km or more. Cenotes are formed by dissolution of rock and the resulting subsurface void, which may or may not be linked to an active cave system, the subsequent structural collapse. Rock that falls into the water below is removed by further dissolution, creating space for more collapse blocks; the rate of collapse increases during periods when the water table is below the ceiling of the void, since the rock ceiling is no longer buoyantly supported by the water in the void.
Cenotes may be collapsed creating an open water pool, or collapsed with some portion of a rock overhanging above the water. The stereotypical cenotes resemble small circular ponds, measuring some tens of meters in diameter with sheer drops at the edges. Most cenotes, require some degree of stooping or crawling to access the water. In the north and northwest of the Yucatán Peninsula in Mexico, the cenotes overlie vertically extensive voids penetrating 50 to 100 m below the modern water table; however few of these cenotes appear to be connected with horizontally extensive underground river systems, with water flow through them being more dominated by aquifer matrix and fracture flows. In contrast, the cenotes along the Caribbean coast of the Yucatán Peninsula provide access to extensive underwater cave systems, such as Sistema Ox Bel Ha, Sistema Sac Actun/Sistema Nohoch Nah Chich and Sistema Dos Ojos; the Yucatán Peninsula contains a vast coastal aquifer system, density-stratified. The infiltrating meteoric water floats on top of higher-density saline water intruding from the coastal margins.
The whole aquifer is therefore an anchialine system. Where a cenote, or the flooded cave to which it is an opening, provides deep enough access into the aquifer, the interface between the fresh and saline water may be reached; the density interface between the fresh and saline waters is a halocline, which means a sharp change in salt concentration over a small change in depth. Mixing of the fresh and saline water results in a blurry swirling effect caused by refraction between the different densities of fresh and saline waters; the depth of the halocline is a function of several factors: climate and how much meteoric water recharges the aquifer, hydraulic conductivity of the host rock and connectivity of existing cave systems and how effective these are at draining water to the coast, the distance from the coast. In general, the halocline is deeper further from the coast, in the Yucatán Peninsula this depth is 10 to 20 m below the water table at the coast, 50 to 100 m below the water table in the middle of the peninsula, with saline water underlying the whole of the peninsula.
In 1936, a simple morphometry-based classification system for cenotes was presented. Cenotes-cántaro are those with a surface connection narrower than the diameter of the water body; the classification scheme was based on morphometric observations above the water table, therefore incompletely reflects the processes by which the cenotes formed and the inherent hydrogeochemical relationship with the underlying flooded cave networks, which were only discovered in the 1980s and with the initiation of cave diving exploration. Flora and fauna are scarcer than in the open ocean, however marine animals do thrive in caves. In caverns, one can spot mojarras, guppies, cat-fish, small eels and frogs. In the most secluded and darker cenotes, the fauna has evolved special features to live in an environment deprived of natural light. For example, many animals don't have pigmentation and they are blind, so they are equipped with long feelers so that they can find food and make
Bay of Pigs (EP)
Bay of Pigs is an EP by Destroyer released on August 19, 2009, on 12" vinyl. Side A: "Bay of Pigs" - 13:37 Side B: "Ravers" - 7:50 Bay of Pigs is "Destroyer's first foray into the ambient disco market. " Ravers is described as "... some of the more meditative realms of 20th Century classical composition " Ravers is another version of the Trouble in Dreams track "Rivers" with a much slower tempo. Dan Bejar John Collins David Carswell Ted Bois Merge Records EP info Destroyer Lyrics Wiki
Zapata Peninsula is a large peninsula in Matanzas Province, southern Cuba, at 22.30°N 81.38°W / 22.30. Ciénaga de Zapata National Park is located on the peninsula, it is located south of Ensenada de la Broa, east of the gulf of Batabano and north of the Gulf of Cazones. The Bay of Pigs defines its eastern limit. To the north, it is bounded by the Carretera Central highway
A mangrove is a shrub or small tree that grows in coastal saline or brackish water. The term is used for tropical coastal vegetation consisting of such species. Mangroves occur worldwide in the tropics and subtropics between latitudes 25° N and 25° S; the total mangrove forest area of the world in 2000 was 137,800 square kilometres, spanning 118 countries and territories. Mangroves are salt-tolerant trees called halophytes, are adapted to life in harsh coastal conditions, they contain a complex salt filtration system and complex root system to cope with salt water immersion and wave action. They are adapted to the low oxygen conditions of waterlogged mud; the word is used in at least three senses: most broadly to refer to the habitat and entire plant assemblage or mangal, for which the terms mangrove forest biome, mangrove swamp are used, to refer to all trees and large shrubs in the mangrove swamp, narrowly to refer to the mangrove family of plants, the Rhizophoraceae, or more just to mangrove trees of the genus Rhizophora.
The mangrove biome, or mangal, is a distinct saline woodland or shrubland habitat characterized by depositional coastal environments, where fine sediments collect in areas protected from high-energy wave action. The saline conditions tolerated by various mangrove species range from brackish water, through pure seawater, to water concentrated by evaporation to over twice the salinity of ocean seawater; the term "mangrove" comes to English from Spanish, is to originate from Guarani. It was earlier "mangrow", but this word was corrupted via folk etymology influence of the word "grove". Mangrove swamps are found in subtropical tidal areas. Areas where mangals occur include marine shorelines; the intertidal existence to which these trees are adapted represents the major limitation to the number of species able to thrive in their habitat. High tide brings in salt water, when the tide recedes, solar evaporation of the seawater in the soil leads to further increases in salinity; the return of tide can flush out these soils, bringing them back to salinity levels comparable to that of seawater.
At low tide, organisms are exposed to increases in temperature and desiccation, are cooled and flooded by the tide. Thus, for a plant to survive in this environment, it must tolerate broad ranges of salinity and moisture, as well as a number of other key environmental factors—thus only a select few species make up the mangrove tree community. About 110 species are considered "mangroves", in the sense of being a tree that grows in such a saline swamp, though only a few are from the mangrove plant genus, Rhizophora. However, a given mangrove swamp features only a small number of tree species, it is not uncommon for a mangrove forest in the Caribbean to feature only three or four tree species. For comparison, the tropical rainforest biome contains thousands of tree species, but this is not to say mangrove forests lack diversity. Though the trees themselves are few in species, the ecosystem that these trees create provides a home for a great variety of other species. Mangrove plants require a number of physiological adaptations to overcome the problems of anoxia, high salinity and frequent tidal inundation.
Each species has its own solutions to these problems. Small environmental variations within a mangal may lead to differing methods for coping with the environment. Therefore, the mix of species is determined by the tolerances of individual species to physical conditions, such as tidal inundation and salinity, but may be influenced by other factors, such as predation of plant seedlings by crabs. Once established, mangrove roots provide an oyster habitat and slow water flow, thereby enhancing sediment deposition in areas where it is occurring; the fine, anoxic sediments under mangroves act as sinks for a variety of heavy metals which colloidal particles in the sediments have scavenged from the water. Mangrove removal disturbs these underlying sediments creating problems of trace metal contamination of seawater and biota. Mangrove swamps protect coastal areas from erosion, storm surge, tsunamis; the mangroves' massive root systems are efficient at dissipating wave energy. They slow down tidal water enough so its sediment is deposited as the tide comes in, leaving all except fine particles when the tide ebbs.
In this way, mangroves build their own environments. Because of the uniqueness of mangrove ecosystems and the protection against erosion they provide, they are the object of conservation programs, including national biodiversity action plans. Mangrove swamps' effectiveness in terms of erosion control can sometimes be overstated. Wave energy is low in areas where mangroves grow, so their effect on erosion is measured over long periods, their capacity to limit high-energy wave erosion is in relation to events such as storm surges and tsunamis. The unique ecosystem found in the intricate mesh of mangrove roots offers a quiet marine region for young organisms. In areas where roots are permanently submerged, the organisms they host include algae, oysters and bryozoans, which all require a hard surface for anchoring while they filter feed. Shrimps and mud lobsters use the muddy bottoms as their home. Mangrove crabs munch on the mangrove leaves, adding nutrients to the mangal muds for other bottom feeders.
In at least some cases, export of carbon fixed in mangroves is imp
Pterois is a genus of venomous marine fish known as lionfish, native to the Indo-Pacific. Called zebrafish, turkeyfish, tastyfish or butterfly-cod, it is characterized by conspicuous warning coloration with red, creamy, or black bands, showy pectoral fins, venomous spiky fin rays. Pterois radiata, Pterois volitans, Pterois miles are the most studied species in the genus. Pterois species are popular aquarium fish. P. volitans and P. miles are a recent and significant invasive species in the west Atlantic, Caribbean Sea and Mediterranean Sea. There are 12 recognized species in this genus: Pterois andover G. R. Allen & Erdmann, 2008 – Andover lionfish Pterois antennata – Spot-fin lionfish Pterois brevipectoralis Pterois cincta Rüppell, 1838 – Red Sea lionfish Pterois lunulata Temminck & Schlegel, 1843 – Luna lionfish Pterois miles – Devil firefish Pterois mombasae – African lionfish, frill-fin turkeyfish Pterois paucispinula Matsunuma & Motomura, 2014 Pterois radiata G. Cuvier, 1829 – Clear-fin lionfish Pterois russelii E. T. Bennett, 1831 – Plaintail turkeyfish, soldier lionfish, or Russell's lionfish Pterois sphex D. S. Jordan & Evermann, 1903 – Hawaiian turkeyfish Pterois volitans – Red lionfish Pterois fish in the Atlantic range from 5 to 45 cm in length, weighing from 0.025 to 1.3 kg.
They are well known for their ornate beauty, venomous spines, unique tentacles. Juvenile lionfish have a unique tentacle located above their eye sockets that varies in phenotype between species; the evolution of this tentacle is suggested to serve to continually attract new prey. Pterois species can have complex courtship and mating behaviors. Females release two mucus-filled egg clusters which can contain as many as 15,000 eggs. Studies on Pterois reproductive habits have increased in the past decade. All the species are aposematic: they have conspicuous coloration with boldly contrasting stripes and wide fans of projecting spines, advertising their ability to defend themselves. According to a study that involved the dissection of over 1,400 lionfish stomachs from Bahamian to North Carolinian waters, Pterois fish prey on small fish and mollusks in large amounts, with some specimens’ stomachs containing up to six different species of prey; the amount of prey in lionfish stomachs over the course of a day suggests lionfish feed most from 7:00–11:00 a.m. and decrease feeding throughout the afternoon.
Lionfish are skilled hunters, using specialized bilateral swim bladder muscles to provide precise control of location in the water column, allowing the fish to alter its center of gravity to better attack prey. The lionfish spreads its large pectoral fins and swallows its prey in a single motion, they blow jets of water while approaching prey to disorient them. In addition to confusing prey, these jets of water alter the orientation of the prey so that the smaller fish is facing the lionfish; this results in a higher degree of predatory efficiency as head-first capture is easier for the lionfish. Aside from instances of larger lionfish individuals engaging in cannibalism on smaller individuals, adult lionfish have few identified natural predators from the effectiveness of their venomous spines. Moray eels, bluespotted cornetfish, large groupers, like the tiger grouper and Nassau grouper, have been observed preying on lionfish, it remains unknown, how these predators prey on lionfish. Sharks are believed to be capable of preying on lionfish with no ill effects from their spines.
Park officials of the Roatan Marine Park in Honduras have attempted to train sharks to feed on lionfish as of 2011 in an attempt to control the invasive populations in the Caribbean. The Bobbit worm, an ambush predator, has been filmed preying upon lionfish in Indonesia. Predators of larvae and juvenile lionfish remain unknown, but may prove to be the primary limiting factor of lionfish populations in their native range. Parasites of lionfish have been observed and are assumed to be infrequent, they include leeches. Lionfish are known for their venomous fin rays, an uncommon feature among marine fish in the East Coast coral reefs; the potency of their venom makes them excellent predators and hazardous to divers. Pterois venom produced negative inotropic and chronotropic effects when tested in both frog and clam hearts and has a depressing effect on rabbit blood pressure; these results are thought to be due to nitric oxide release. In humans, Pterois venom can cause systemic effects such as extreme pain, vomiting, breathing difficulties, dizziness, redness on the affected area, numbness, heartburn and sweating.
Such stings can cause temporary paralysis of the limbs, heart failure, death. Fatalities are common in young children, the elderly, those with a weak immune system, or those who are allergic to their venom, their venom is fatal to healthy adults, but some species have enough venom to produce extreme discomfort for a period of several days. However, Pterois venom is a danger to allergic victims as they may experience anaphylaxis, a serious and life-threatening condition that requires immediate emergency medical treatment. Severe allergic reactions to Pterois venom include chest pain, severe breathing difficulties