|
Dungeness Crab
The Dungeness crab (''Metacarcinus magister'') makes up one of the most important seafood industries along the west coast of North America. Its typical range extends from Alaska's Aleutian Islands to Point Conception, near Santa Barbara, California. Dungeness typically grow at their widest point and inhabit eelgrass beds and sandy bottoms. Its common name comes from the Dungeness Spit in the Strait of Juan de Fuca, Washington state, United States, which shelters a shallow bay inhabited by the crabs. Description Dungeness crabs have four pairs of armored legs, two claws, and a wide, hard shell. A Dungeness's legs are shorter compared to other commercial crabs and their claws have a distinctive hook. The claws of the crab are used both as defense and to tear apart large food items. The crab uses its smaller appendages to pass the food particles into its mouth. Once inside the crab's stomach, food is further digested by the " gastric mill", a collection of tooth-like structures. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Dwight Dana
James Dwight Dana Royal Society of London, FRS FRSE (February 12, 1813 – April 14, 1895) was an American geologist, mineralogist, volcanologist, and zoologist. He made pioneering studies of mountain-building, volcano, volcanic activity, and the origin and structure of continents and oceans around the world. His zoological author abbreviation is Dana. Early life and career Dana was born February 12, 1813, in Utica, New York. His father was merchant James Dana (1780–1860) and his mother was Harriet Dwight (1792–1870). Through his mother he was related to the Dwight New England family of missionaries and educators including uncle Harrison Gray Otis Dwight and first cousin Henry Otis Dwight. He showed an early interest in science, which had been fostered by Fay Edgerton, a teacher in the Utica high school, and in 1830 he entered Yale College in order to study under Benjamin Silliman the elder. Graduating in 1833, for the next two years he was teacher of mathematics to midshi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean
Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthropods including decapods (shrimps, prawns, crabs, lobsters and crayfish), seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, opossum shrimps, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods (insects and entognathans) emerged deep in the Crustacean group, with the completed pan-group referred to as Pancrustacea. The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans ( oligostracans and multicrustaceans). The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intertidal Zone
The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various species of life, such as sea stars, sea urchins, and many species of coral with regional differences in biodiversity. Sometimes it is referred to as the ''littoral zone'' or '' seashore'', although those can be defined as a wider region. The intertidal zone also includes steep rocky cliffs, sandy beaches, bogs or wetlands (e.g., vast mudflats). This area can be a narrow strip, such as in Pacific islands that have only a narrow tidal range, or can include many meters of shoreline where shallow beach slopes interact with high tidal excursion. The peritidal zone is similar but somewhat wider, extending from above the highest tide level to below the lowest. Organisms in the intertidal zone are well-adapted to their environment, facing high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean Larvae
Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults (on the sea bed), more-so than where the larvae are planktonic, and thereby easily caught. Many crustacean larvae were not immediately recognised as larvae when they were discovered, and were described as new genera and species. The names of these genera have become generalised to cover specific larval stages across wide groups of crustaceans, such as ''zoea'' and ''nauplius''. Other terms described forms which are only found in particular groups, such as the ''glaucothoe'' of hermit crabs, or the '' phyllosoma'' of slipp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diel Vertical Migration
Diel vertical migration (DVM), also known as diurnal vertical migration, is a pattern of movement used by some organisms, such as copepods, living in the ocean and in lakes. The adjective "diel" ( IPA: , ) comes from , and refers to a 24-hour period. The migration occurs when organisms move up to the uppermost layer of the water at night and return to the bottom of the daylight zone of the oceans or to the dense, bottom layer of lakes during the day. DVM is important to the functioning of deep-sea food webs and the biologically-driven sequestration of carbon. In terms of biomass, DVM is the largest synchronous migration in the world. It is not restricted to any one taxon, as examples are known from crustaceans (copepods), molluscs (squid), and ray-finned fishes (trout). The phenomenon may be advantageous for a number of reasons, most typically to access food and to avoid predators. It is triggered by various stimuli, the most prominent being changes in light-inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spermatheca
The spermatheca (pronounced : spermathecae ), also called ''receptaculum seminis'' (: ''receptacula seminis''), is an organ of the female reproductive tract in insects, e.g. ants, bees, some molluscs, Oligochaeta worms and certain other invertebrates and vertebrates. Its purpose is to receive and store sperm from the male or, in the case of hermaphrodites, the male component of the body. Spermathecae can sometimes be the site of fertilisation when the oocytes are sufficiently developed. Some species of animal have multiple spermathecae. For example, certain species of earthworms have four pairs of spermathecae—one pair each in the 6th, 7th, 8th, and 9th segments. The spermathecae receive and store the spermatozoa of another earthworm during copulation. They are lined with epithelium and are variable in shape: some are thin, heavily coiled tubes, while others are vague outpocketings from the main reproductive tract. It is one of the many variations in sexual reproduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pheromone
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavior of the receiving individuals. There are ''alarm signal, alarm pheromones'', ''food trail pheromones'', ''sex pheromones'', and many others that affect behavior or physiology. Pheromones are used by many organisms, from basic unicellular prokaryotes to complex multicellular eukaryotes. Their use among insects has been particularly well documented. In addition, some vertebrates, plants and ciliates communicate by using pheromones. The ecological functions and evolution of pheromones are a major topic of research in the field of chemical ecology. Background The portmanteau word "pheromone" was coined by Peter Karlson and Martin Lüscher in 1959, based on the Greek language, Greek () and (). Pheromones are also sometimes classified as ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoskeleton
An exoskeleton () . is a skeleton that is on the exterior of an animal in the form of hardened integument, which both supports the body's shape and protects the internal organs, in contrast to an internal endoskeleton (e.g. human skeleton, that of a human) which is enclosed underneath other soft tissues. Some large, hard and non-flexible protective exoskeletons are known as mollusc shell, shell or armour (anatomy), armour. Examples of exoskeletons in animals include the arthropod exoskeleton, cuticle skeletons shared by arthropods (insects, chelicerates, myriapods and crustaceans) and tardigrades, as well as the corallite, skeletal cups formed by hardened secretion of stony corals, the test (biology), test/tunic of sea squirts and sea urchins, and the prominent mollusc shell shared by snails, bivalvia, clams, tusk shells, chitons and nautilus. Some vertebrate animals, such as the turtle, have both an endoskeleton and a turtle shell, protective exoskeleton. Role Exoskeletons c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dungeness Crab (Metacarcinus Magister) With Eggs
The Dungeness crab (''Metacarcinus magister'') makes up one of the most important seafood industries along the west coast of North America. Its typical range extends from Alaska's Aleutian Islands to Point Conception, near Santa Barbara, California. Dungeness typically grow at their widest point and inhabit eelgrass beds and sandy bottoms. Its common name comes from the Dungeness Spit in the Strait of Juan de Fuca, Washington state, United States, which shelters a shallow bay inhabited by the crabs. Description Dungeness crabs have four pairs of armored legs, two claws, and a wide, hard shell. A Dungeness's legs are shorter compared to other commercial crabs and their claws have a distinctive hook. The claws of the crab are used both as defense and to tear apart large food items. The crab uses its smaller appendages to pass the food particles into its mouth. Once inside the crab's stomach, food is further digested by the " gastric mill", a collection of tooth-like structures. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rostrum (anatomy)
Rostrum (from Latin ', meaning '':wikt:beak, beak'') is a term used in anatomy for several kinds of hard, beak-like structures projecting out from the head or mouth of an animal. Despite some visual similarity, many of these are Phylogenetics, phylogenetically unrelated structures in widely varying species. Invertebrates * In spiders, the rostrum is a part of the mouth of which it borders the opening in front. Homologous of an upper lip, this outgrowth is especially characterised by the presence of a pocket-shaped secreting organ, the rostral gland, only accessible by the sole means of histology and electron microscopy (external link "archentoflor"). * In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes. It is generally a rigid structure, but can be connected by a hinged joint, as seen in Leptostraca. * Among insects, the rostrum is the name for the piercing insect mouthparts, mouthparts of the order Hemiptera as well as those of the snow s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antennule
An antenna (plural: antennae) is one of a pair of appendages used for sensing in arthropods. Antennae are sometimes referred to as ''feelers''. Antennae are connected to the first one or two segments of the arthropod head. They vary widely in form but are always made of one or more jointed segments. While they are typically sensory organs, the exact nature of what they sense and how they sense it is not the same in all groups. Functions may variously include sensing touch, air motion, heat, vibration (sound), and especially smell or taste. Antennae are sometimes modified for other purposes, such as mating, brooding, swimming, and even anchoring the arthropod to a substrate. Larval arthropods have antennae that differ from those of the adult. Many crustaceans, for example, have free-swimming larvae that use their antennae for swimming. Antennae can also locate other group members if the insect lives in a group, like the ant. The common ancestor of all arthropods likely had on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recruitment (biology)
When discussing population dynamics, behavioral ecology, and cell biology, recruitment refers to several different biological processes. In population dynamics, recruitment is the process by which new individuals are added to a population, whether by birth and maturation or by immigration. When discussing behavioral ecology and animal communication, recruitment is communication that is intended to add members of a group to specific tasks. Finally, when discussing cell biology, recruitment is the process by which cells are selected for certain tasks. Recruitment in population dynamics Definition and importance In population dynamics and community ecology, recruitment is the process by which individuals are added to a population. Successful recruitment is contingent on an individual surviving and integrating within the population; in some studies, individuals are only considered to have been recruited into a population once they've reached a certain size or life stage. Recruitmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
