26 Sentences With "antennule" | Random Sentence Generator

In the presence of certain amino acids, the neurons of the antennule fire.

It counts with setae natatoriae about 2.1–2.3 the length of the preanal portion of its postabdomen. Its antennule is long and narrow, nearly reaching the tip of the rostrum; the antennular seta is thin, of about half the length of the antennule. It exhibits nine terminal aesthetascs, the two longest being about 2/3 the length of the antennule itself. All the aesthetascs project beyond the anterior margin of the head shield.

The sixth stage has a segmented inner flagellum of the antennule and fully developed pleopods with setae.

Furthermore, juveniles with a long antennule and a mucro were classified as being of the species Bosmina coregoni.

The synapomorphy of the taxon Ecbathyriontidae – Dirivultidae is the presence of a double segment in the female antennule.

An exact count of antennular articles is not possible because the antennule is never complete and articles are poorly preserved distally.

Each antennule sports thousands of hairlike odor sensors, which give the lobster an extraordinarily sensitive sense of smell by which to navigate.

Olfactory responses of lobsters to solutions from prey species and to seawater extracts and chemical fractions of fish muscle and effects of antennule ablation.

If it is in its natural position, it is not an antennule, but the endopodite of the second or third pair of cephalic appendages.

The antennule is the shorter pair compared to the longer antenna and is shorter than all the pleopod lamellae. The antennule is slender and weak and extends to the seventh article on the other larger pair. E. californica has maxillipeds composed of two articles while the mandible has palps made up by three articles. The thorax is that of a typical Elthusa genus organism.

The second or deutocerebral appendage includes the jaw of onychophorans, the raptorial appendage of megacheirans, the antenna of insects and myriapods and the antennule of crustaceans, and the chelicera of chelicerates.

It is believed that Kiisortoqia was a predatory swimmer. The large paddle-like exopods were probably suitable for swimming. With its robust antennule, K. soperi could capture prey, probably using its prickly basipods to bring them to its mouth.

Longiflagrum amphibium can be distinguished from the other four species of the genus Longiflagrum by having the shortest flagellum in the antennule and by its oval pleopod basis. The specific name ' is from the Latin for "amphibious". The name reflects the species' presence in the intertidal zone.

The species' head, antennule and labrum is the same as for the genus. The postabdomen narrows distally, the length of which is about 3.2 its height. Setules near the base of its postabdominal claws are short. Its antenna comprises less than 1/5 of its body length.

Males are 1.2 mm, and ovigerous females are 1.6 mm in total length. The antennule has a single terminal aesthetasc. The mandible lacks palpi; the incisor has four cusps and a spine-row of three or four spines; the molar is stout and distally truncated. The pereon dorsally lacks setae.

They have been suggested to be homologous with the antennule of the euarthropods, or the chelicerae of chelicerates, although the latter possibility had been discounted by some authors. Later observations reject the homology of this two type of "great appendages", with neural structures clarifying the segmental affinities of radiodont frontal appendages as protocerebral (homologous to euarthropod's labrum), and megacheiran's short-great appendages as deutocerebral (homologous to euarthropod's antennule and chelicerae). Similar appendages also found in other Cambrian arthropods such as Isoxys and Occacaris, but their segmental affinities remain conjectural. On the other hand, a 2020 study suggested that the great/frontal appendages of Megacheirans, Isoxyids and Radiodontans to be homologous, and that the presence of a great appendage is the ancestral condition for Euarthropoda.

In most species, there are two eyes at the front side of the head shield, often merged into a single dorsal eye lobe. The five posterior somites of the thorax form the pereon. The pleon (abdomen) consists of six cylindrical somites. The first antenna (antennule) has two flagella, the outer flagellum usually being longer than the inner one.

A cluster of short setules is located near the base of the postabdominal claws. The latter is long, almost straight, longer than the anal portion of the postabdomen. The spine at the end of the pecten is short. The antennule is long and narrow, with a length equating to about 4 widths, including 3 transverse rows of short setules at its anterior face.

Macrocyclops is a member of Crustacea: Copepoda. The genus Macrocyclops is characterized by a fifth leg of two distinct segments, the distal segment bearing three spines or setae on its terminal end. Macrocyclops albidus is distinguished by the bare medial surface of the caudal rami and the hyaline membrane on the last segment of the antennule, which is smooth or finely serrated.

The first segment bore a ventral pair of large limbs, known as the antennule, which are about half to two- thirds as long as the body. They consisted of a cylindrical stem and about 15 segments. The segments had a flat outer side and two widely spaced spines. The other limbs – three pairs in the head region shield and 16 on the body segments – composed of two branches.

In spite of this, the ovigerous females must release the fertilized eggs in the ocean for the larvae to develop (as with all known species of terrestrial hermit crabs). The species is presumably named for the dark red coloration of their exoskeleton. Under Greeff's original observation, this species has a more elongated antennule and the left cheliped lacks the stridulation ridges (as such seen in C. rugosus), leading to the distinction. At approximately , they are rather small by Coenobita standards.

A male cyprid larva settles on the externa and fertilises the eggs by antennule penetration, the larvae developing inside the brood chamber. Here they develop directly into cyprid larvae, missing out the nauplius stage of more typical crustaceans. The cyprid larvae are at first unisex, becoming male or female according to what role they play in the reproductive cycle. The presence of this parasite effectively sterilises the host hermit crab, the gonads do not degenerate, but they fail to produce mature eggs and sperm.

Close-up of the head: the two eyes sit on eyestalks, with an antennule on either side of the rostrum (center, above the mouth) The carapace widths of mature Dungeness crabs may reach in some areas off the coast of Washington, but are typically under . They are a popular delicacy, and are the most commercially important crab in the Pacific Northwest, as well as the western states generally. The annual Dungeness Crab and Seafood Festival is held in Port Angeles, Washington each October. Dungeness crabs have a wide, long, hard shell, which they must periodically moult to grow; this process is called ecdysis.

Diagram of Nebalia bipes showing the major features of the external anatomy: 1: antennule; 2: rostrum; 3: carapace; 4: abdomen / pleon; 5: furca; 6: telson; 7: pleopods; 8: antenna; 9: thoracopods; 10: eye Leptostracans are usually small, typically long, crustaceans distinguished from all other members of their class in having seven abdominal segments, instead of six. Their head has stalked compound eyes, two pairs of antennae (one biramous, one uniramous), and a pair of mandibles but no maxillipeds. The carapace is large and comprises two valves which cover the head and the thorax, including most of the thoracic appendages, and serves as a brood pouch for the developing embryos. The first six abdominal segments bear pleopods, while the seventh bears a pair of caudal furcae, which may be homologous to uropods of other crustaceans.

Diagram of Nebalia bipes showing the major features of the external anatomy: 1: antennule; 2: rostrum; 3: carapace; 4: abdomen / pleon; 5: furca; 6: telson; 7: pleopods; 8: antenna; 9: thoracopods; 10: eye The Phyllocarida is a group of about 36 small marine species that are distributed across planet and possess a characteristic large bivalve carapace and an elongated abdomen with no uropods. This group is believed to be the most primitive malacostracan group, because they lack some of the caridoid facies, such as the presence of seven abdominal segments (eight if telson is included). Furthermore, one study by Willsplaces them as a sister branch to the Cephalocarida and basal to a Maxillopoda + Eumalacostraca clade and therefore making the Malacostraca paraphyletic. The Eumalacostraca — the malacostraca minus the phyllocarida — were subdivided on the basis of several features, although which group is basal is unclear.