Jassa falcata
Encyclopedia
Jassa falcata, commonly known as scud, is a tube-dwelling amphipod
in the genus
Jassa
.
Jassa falcata is one of the thousands of species
of amphipod. Like lobster
s, crab
s and shrimp
s, amphipods are crustacean
s in the class
Malacostraca
.
Jassa falcata constructs tubes of debris
. It is a fouling organism
, growing on the bottoms of ships and slowing them down. J. falcata forms dense mats or nests. The male and the female live in different tubes. J. falcata feeds generally on hydroid
growth on the bottom of rafts and ships. It is generally a suspension feeder normally found on sediment areas.
Amphipods have two pairs of antennae
. In J. falcata the first antennae have two-segmented flagella
and are shorter and more slender than the second antennae. Males are 7–13 mm long and females are 6–12 mm. Colors vary but are usually yellow-grey with brown, red or black patches depending on the color of the habitat.
Amphipoda
Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. The name amphipoda means "different-footed", and refers to the different forms of appendages, unlike isopods, where all the legs are alike. Of the 7,000 species, 5,500 are classified...
in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Jassa
Jassa
Jassa is a genus of amphipods in the family Ischyroceridae, comprising the following species:*Jassa algensis *Jassa alonsoae Conlan, 1990*Jassa australis *Jassa barnardi Stephensen, 1949...
.
Jassa falcata is one of the thousands of species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of amphipod. Like lobster
Lobster
Clawed lobsters comprise a family of large marine crustaceans. Highly prized as seafood, lobsters are economically important, and are often one of the most profitable commodities in coastal areas they populate.Though several groups of crustaceans are known as lobsters, the clawed lobsters are most...
s, crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s and shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
s, amphipods are crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s in the class
Class (biology)
In biological classification, class is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order...
Malacostraca
Malacostraca
Malacostraca is the largest of the six classes of crustaceans, containing over 25,000 extant species, divided among 16 orders. Its members display a greater diversity of body forms than any other class of animals, and include crabs, lobsters, shrimp, krill, woodlice, scuds , mantis shrimp and many...
.
Jassa falcata constructs tubes of debris
Debris
Debris is rubble, wreckage, ruins, litter and discarded garbage/refuse/trash, scattered remains of something destroyed, or, in geology, large rock fragments left by a melting glacier etc. The singular form of debris is debris...
. It is a fouling organism
Biofouling
Biofouling or biological fouling is the undesirable accumulation of microorganisms, plants, algae, or animals on wetted structures.-Impact:...
, growing on the bottoms of ships and slowing them down. J. falcata forms dense mats or nests. The male and the female live in different tubes. J. falcata feeds generally on hydroid
Hydroid
-Marine biology:Hydroids are a life stage for most animals of class Hydrozoa, small predators related to jellyfish.-Botany:In mosses, hydroids form the innermost layer of the stem of long, colourless, thin walled cells of small diameter.The cells are dead and lack protoplasm.They function as water...
growth on the bottom of rafts and ships. It is generally a suspension feeder normally found on sediment areas.
Amphipods have two pairs of antennae
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
. In J. falcata the first antennae have two-segmented flagella
Flagellum
A flagellum is a tail-like projection that protrudes from the cell body of certain prokaryotic and eukaryotic cells, and plays the dual role of locomotion and sense organ, being sensitive to chemicals and temperatures outside the cell. There are some notable differences between prokaryotic and...
and are shorter and more slender than the second antennae. Males are 7–13 mm long and females are 6–12 mm. Colors vary but are usually yellow-grey with brown, red or black patches depending on the color of the habitat.