Peramphithoe femorata | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Malacostraca |
Superorder: | Peracarida |
Order: | Amphipoda |
Family: | Ampithoidae |
Genus: | Sunamphitoe |
Species: | S. femorata |
Binomial name | |
Sunamphitoe femorata | |
Synonyms [1] | |
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Sunamphitoe femorata is a species of amphipod crustacean in the family Ampithoidae. [2] It is a herbivore and constructs a tubular nest-like home on a blade of the sporophyte of the giant kelp Macrocystis pyrifera . This home is made by rolling the sides of the blade together and securing them with silk. As the kelp blade grows, the nest is advanced down the blade towards the base, approximately keeping pace with the algal growth.
The species was originally described in 1845 as Ampithoe femorata by Henrik Nikolai Krøyer and moved to Peramphithoe femorata' in 1982. [3] Following a phylogenetic analysis that found neither Peramphithoe nor Sunamphitoe monophyletic, with the species intermingled within a clade, the two genera were synonymised and Peramphithoe femorata renamed Sunamphitoe femorata. [3] [4]
Sunamphitoe femorata has been reported from the Caribbean Sea, Venezuela and the Southern Ocean. [1]
Sunamphitoe femorata is a tubicolous (tube-forming) amphipod that feeds and makes its home on the giant kelp Macrocystis pyrifera . This brown alga is found in shallow water and can grow to a length of 45 m (148 ft) in a single season. It is attached to the substrate by a holdfast from which grow several long slender stems. These are clad in numerous small leaf-like blades growing from pneumatocysts (gas-filled bladders) [5] and it is on these blades that the amphipod lives. The blades grow continuously from near their bases and the amphipod chooses a position some way along a blade, rolling the edges together to form a tube. It first deposits a mass of silk on the blade and grips this with its 5th, 6th and 7th pereopods. It then secures the edges of the blade to each other with a silken thread, produced from glands on the third and fourth pairs of pereopods, manipulating the thread with the first and second pairs. The weaving process continues rhythmically at the rate of about 24 silk attachments per minute, alternately on the left and right sides of the blade, and a tube is formed. [6]
The meristem from which the blade grows is just above the junction with the pneumatocyst. The rate of elongation of the blade decreases over time and for about six days the nest is extended towards the base of the blade at about the same rate as the blade is growing. After that the rate of growth of the blade slows down further and the rate of nest advancement becomes more variable. At the entrance of the nest (the end nearest the base of the blade) the surface layer of the blade is grazed by the amphipod while at the other end of the nest the central tissue of the blade is also consumed. The oldest part of the blade becomes senescent and sloughs off. The amphipod does not occupy the nest continuously but sometimes moves elsewhere on the host kelp, leaving a small grazing scar to show where it has foraged. Sometimes the nest is abandoned and a new nest may be built in a different location. Researchers studying this amphipod (Cerda, Hinojosa & Thiel, 2012) hypothesised that the position chosen for the nest might be a location where the maximum nutritional value of the tissue coincided with a decrease in production of defensive chemicals by the alga. [6]
Kelps are large brown algae or seaweeds that make up the order Laminariales. There are about 30 different genera. Despite its appearance, kelp is not a plant but a stramenopile, a group containing many protists.
Brown algae, comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar regions. They are dominant on rocky shores throughout cooler areas of the world. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, Macrocystis, a kelp of the order Laminariales, may reach 60 m (200 ft) in length and forms prominent underwater kelp forests. Kelp forests like these contain a high level of biodiversity. Another example is Sargassum, which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Some members of the class, such as kelps, are used by humans as food.
Nereocystis is a monotypic genus of subtidal kelp containing the species Nereocystis luetkeana. Some English names include edible kelp, bull kelp, bullwhip kelp, ribbon kelp, bladder wrack, and variations of these names. Due to the English name, bull kelp can be confused with southern bull kelps, which are found in the Southern Hemisphere. Nereocystis luetkeana forms thick beds on subtidal rocks, and is an important part of kelp forests.
Macrocystis is a monospecific genus of kelp with all species now synonymous with Macrocystis pyrifera. It is commonly known as giant kelp or bladder kelp. This genus contains the largest of all the phaeophyceae or brown algae. Macrocystis has pneumatocysts at the base of its blades. Sporophytes are perennial and the individual may live for up to three years; stipes/fronds within a whole individual undergo senescence, where each frond may persist for approximately 100 days. The genus is found widely in subtropical, temperate, and sub-Antarctic oceans of the Southern Hemisphere and in the northeast Pacific from Baja California to Sitka, Alaska. Macrocystis is often a major component of temperate kelp forests.
Gammaridea is one of the suborders of the order Amphipoda, comprising small, shrimp-like crustaceans. Until recently, in a traditional classification, it encompassed about 7,275 (92%) of the 7,900 species of amphipods described by then, in approximately 1,000 genera, divided among around 125 families. That concept of Gammaridea included almost all freshwater amphipods, while most of the members still were marine.
Acanthonotozomellidae is a family of amphipod crustaceans. A new species was discovered deep in Drake Passage in 2001, with small teeth covering its body. As of 2022, four genera and eight species are currently recognized.
Bateidae is a family of amphipod crustaceans, comprising the single genus Batea, which in turn contains thirteen species:
Eophliantidae is a family of amphipods, containing the following genera:
Phliantidae is a family of isopod-like amphipod crustaceans chiefly from the southern hemisphere.
Pardaliscidae is a family of amphipods, whose members typically inhabit the deepest parts of ocean basins. It contains the following genera:
Photis is a genus of amphipod crustaceans, containing the following species:
The marine snail Norrisia norrisii is a medium-sized gastropod mollusk within the family Tegulidae. It has several common names, including Norris's top snail, Norris's topsnail, norrissnail, smooth brown turban snail, or kelp snail. It was first described by G.B. Sowerby I under the name Trochiscus norrisii.
Alicella gigantea is the largest species of amphipod ever observed, with some individuals reaching up to 34 centimetres (13 in) long. The average length of A. gigantea ranges from 72.5 to 141.0 millimeters, and its weight ranges from 4.2 to 45 grams[4]. Comparatively to other amphipods, the A. gigantea grows at a much faster rate. Formerly included in the family Lysianassidae, a new family, Alicellidae, was erected in 2008 for Alicella and five related genera. The species lives only at great depths; the first specimens were collected at the end of the 19th century from the Madeira Abyssal Plain, and subsequent specimens have been found in other abyssal plains of both the Atlantic and Pacific Oceans, as well as from the Kermadec Trench in the southwest Pacific. One specimen was found in the stomach of a black-footed albatross, but is thought to have been dead before it was eaten.
Atylidae is a family of amphipod crustaceans, containing the following genera:
Photidae is a family of amphipod crustaceans, containing the following genera:
Caprelloidea is a superfamily of marine crustaceans in the order Amphipoda. It includes "untypical" forms of amphipods, such as the skeleton shrimps (Caprellidae) and whale lice (Cyamidae). The group was formerly treated as one of the four amphipod suborders, Caprellidea, but has been moved down to the superfamily rank by Myers & Lowry after phylogenetic studies of the group, and is now contained in the infraorder Corophiida of the suborder Senticaudata. The group includes the following families.
Martensia martensi is a species of amphipod crustacean, and the only species in the genus Martensia. It occurs in waters around Svalbard at depths of 37–95 metres (121–312 ft).
Pseudamphithoides incurvaria is a species of amphipod crustacean in the family Ampithoidae. It is native to shallow water in the tropical western Atlantic Ocean where it creates a home for itself from fragments of the algae on which it feeds. This seaweed contains certain chemicals that are distasteful and protect it from predatory fish.
Ampithoidae is a family of amphipod crustaceans. The family has a worldwide distribution as algal dwellers. They commonly create tube-shaped nests on their host plants or algae which serve as both shelter and food. Young ampithoids develop from eggs to a larval stage within their mother's brood-pouch, formed by the appendages of her abdomen.