The

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

''Glycera'' is a group of

polychaete Polychaeta () is a paraphyletic class (biology), class of generally marine invertebrate, marine annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that ...

s (bristle worms) commonly known as bloodworms. They are typically found on the bottom of shallow marine waters, and some species (e.g. common bloodworms) can grow up to 35 cm (14 in) in length.

Anatomy

Bloodworms have a creamy pink color, as their pale skin allows their red body fluids that contain

haemoglobin Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocyte ...

to show through. This is the origin of the name "bloodworm". At the 'head', bloodworms have four small antennae and small fleshy projections called

parapodia In invertebrates, the term parapodium ( Gr. ''para'', beyond or beside + ''podia'', feet; plural: parapodia) refers to lateral outgrowths or protrusions from the body. Parapodia are predominantly found in annelids, where they are paired, unjointed ...

running down their bodies. Bloodworms can grow up to in length. Bloodworms are carnivorous. They feed by extending a large

proboscis A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elong ...

that bears four hollow jaws. The jaws are connected to glands that supply venom which they use to kill their prey, and their bite is painful even to a human. They are preyed on by other worms, bottom-feeding

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

crustacea Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...

, and

gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century, m ...

s. Reproduction occurs in midsummer, when the warmer water temperature and lunar cycle among other factors triggers sexually mature worms to transform into a non-feeding stage called the

epitoke Epitoky is a process that occurs in many species of polychaete marine worms wherein a sexually immature worm (the atoke) is modified or transformed into a sexually mature worm (the epitoke). Epitokes are pelagic morphs capable of sexual reproduc ...

. With enlarged

, they swim to the surface of the water where both sexes release

gamete A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce t ...

s, and then die. The first stage in many forms of bloodworm is a zooplanktonic stage followed by the benthic instar where the familiar segmented red larvae develop protected by silk tubes made in the bottom silt. These larvae progress from tiny pale opaque worms to the larger red larvae of 3 to 10 centimeters in length or longer over a period as short as 2–3 weeks in optimum conditions. These animals are unique in that they contain a lot of copper without being poisoned. Their jaws are unusually strong since they too contain the metal in the form of a copper-based chloride biomineral, known as

atacamite Atacamite is a copper halide mineral: a copper(II) chloride hydroxide with formula Cu2Cl(OH)3. It was first described for deposits in the Atacama Desert of Chile in 1801 by D. de Fallizen. The Atacama Desert is also the namesake of the mineral. ...

, in crystalline form. It is theorized that this copper is used as a catalyst for its venomous bite. In ''Glycera dibranchiata'', the jaws are a composite of melanin and 10% copper.

Systematics

''Glycera'' is the

type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal f ...

of the family

Glyceridae Glyceridae is a family of polychaete worms. They are commonly referred to as beak-thrower worms or bloodworms. They are bright red, segmented, aquatic worms. The proboscis worm '' Glycera'' is sometimes called bloodworm. The Glyceridae are epi- a ...

. It contains the following species:

Use by humans

''Glycera'' worms are sold commercially in tackle shops as bait for saltwater fishing.

References

"Fishing for Allergens: Bloodworm-Induced Asthma" study at the Allergy, Asthma & Clinical Immunology (AACI) site {{DEFAULTSORT:Glycera (annelid) Polychaete genera Phyllodocida ru:Glycera alba