Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Crustacea”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50Linked to original sources
PubMed2004

A new hermit crab species of Pylopaguropsis (Crustacea: Decapoda: Anomura: Paguridae) from the western Pacific, and supplemental note on P. laevispinosa McLaughlin and Haig.

Pylopaguropsis vicina, a new species of the Paguridae, is described and illustrated from southern Japan and Indonesia. This new species is most similar to P. laevispinosa McLaughlin and Haig, but is distinguished by the armature of the chelae and ambulatory dactyli, spination of the telson, and stripe pattern of the pereopods. Reexamination of specimens referred to P. laevispinosa by recent authors has shown these assignments to be incorrect. A brief supplemental description is provided for P. laevispinosa in order to clarify its systematic status. An amended key to species of the genus Pylopaguropsis is presented.

Animal Structures↗
PubMed2001

A new distinctive species of pagurid hermit crab (Crustacea: Decapoda: Anomura) from Japan.

A new species of pagurid hermit crab, Pagurus decimbranchiae, is described and illustrated based on 20 specimens collected from shallow waters of the Pacific coast of Japan ranging from Boso Peninsula to Tanegashima Island. It is quite distinctive in having the rudimentary arthrobranch on the third maxilliped represented by a single bud, however close morphological similarity is found between the new species and P. moluccensis Haig and Ball. Comparisons are also made among other species, including P. boriaustraliensis Morgan, P. sp. cf. boriaustraliensis sensu Rahayu and Komai (2000) and the members of the P. anachoretus group. The present generic assignment of the new species should be considered provisional, as more extensive study is needed to investigate phylogenetic relationships of the new species and the other species of Pagurus.

Animals↗
PubMed2002

Three new species of the genus Gammarus (Crustacea, Amphipoda, Gammaridae) from Yunnan, China.

Three new species of the genus Gammarus are described from Lijiang, Yunnan Province, South China. Gammarus elevatus sp. nov. is characterized by mid-dorsal keel on pleonites 1-3 and compressed elevation on urosomites 1-2; G. denticulatus sp. nov. by many small spinules and setae on pleonites 1-3; G. stagnarius sp. nov. by lack of calceoli on antenna 2 and shorter inner ramus of uropod 3. These amphipods are compared with other known Gammarus species from China.

Amphipoda↗
PubMed2003

A marine harpacticoid, Quinquelaophonte koreana sp. nov. from a sandy beach in Korea (Crustacea: Copepoda).

A new interstitial copepod of the family Laophontidae was found in the samples from a sandy beach at Taean, west coast of Korea. This species was described and named as Quinquelaophonte koreana sp. nov. Present new species is clearly distinguishable from its congeners with the combined characters of the short caudal ramus and its short ornamented seta V, two setae on the antennary exopod, and small rounded rostrum. Q. koreana sp. nov. is the first record of Quinquelaophonte from the Northeast Asian coast.

Animals↗
PubMed2003

Syncrangon, a new crangonid genus, with redescriptions of S. angusticauda (De Haan) and S. dentata (Balss) (Crustacea, Decapoda, Caridea) from East Asian waters.

A new genus of the crangonid shrimps, Syncrangon, is proposed for Crangon angusticauda De Haan, 1849 and C. (Sclerocrangon) angusticauda var. dentata Balss, 1914, both from East Asian waters. The new genus is readily distinguished from all known genera of the Crangonidae by the flattened middorsal carina and the deep groove on each lateral side of the middorsal carina on the third to sixth abdominal somites. Syncrangon angusticauda new combination has previously been assigned to the genus Metacrangon, while S. dentata new combination has not been reported since the original description. These two species are easily distinguished from each other by many characters, especially the rostral and abdominal features. They are redescribed and illustrated in detail.

Animals↗
PubMed2004

Isolation and cDNA cloning of ovarian cortical rod protein in kuruma prawn Marsupenaeus japonicus (Crustacea: Decapoda: Penaeidae).

Two cortical rod proteins having molecular weights of 28.6 kDa and 30.5 kDa were isolated from the mature ovary of Marsupenaeus japonicus using gel filtration and reversed-phase HPLC. Analysis of the N-terminal amino acid sequence of the 28.6 kDa molecule revealed that amino acid residues 1-21 corresponded to residues 9-29 of the 30.5 kDa molecule. Examination of homology using BLAST showed that 21 amino acids out of 29 residues of the 28.6 kDa molecule, and 14 out of 29 residues of the 30.5 kDa molecule were identical to that of the ovarian cortical rod proteins of Penaeus semisulcatus. Positive immunohistochemical reaction to antiserum raised against the 28.6 kDa protein was observed on cortical rods forming around the periphery of oocytes at the maturation stages. Western blotting analysis revealed that both the 28.6 kDa and 30.5 kDa molecules stained with the anti-28.6 kDa antiserum. Furthermore, the 28.6 kDa and 30.5 kDa proteins were both glycosylated, as evidenced by positive carbohydrate staining using Concanavalin A and production of positive PAS reaction. These results indicate that the cortical rods are comprised of the 28.6 kDa and 30.5 kDa molecules. We subsequently cloned two full-length cDNAs based on the N-terminal sequences of the 28.6 kDa and 30.5 kDa molecules. The open reading frame of 28.6 kDa and 30.5 kDa encoded 276 amino acid residues. Comparison analysis of the two cDNAs revealed that the location of the processing site and sequence of signal peptides differed, indicating that the two cDNAs are products of two separate genes and encode the 28.6 kDa molecule and 30.5 kDa molecule, respectively. Both proteins possessed one potential N-linked glycosylation site. It is considered that both molecules are components of the cortical rods, forming a jelly layer after fertilization.

Amino Acid Sequence↗
PubMed2004

Periclimenes speciosus, a new species of anthozoan associated shrimp (Crustacea: Decapoda: Palaemonidae) from southern Japan.

A new species of palaemonid shrimp, Periclimenes speciosus sp. nov., is described and illustrated on the basis of 20 specimens collected from warm-temperate and subtropical waters of southern Japan. Periclimenes speciosus belongs to the "P. aesopius species group", and is associated with sea anemones and a scleractinian coral as well as behaving as a fish cleaner. Morphologically, the new species appears closest to P. holthuisi Bruce, 1969, but can be distinguished from P. holthuisi by the form and armature of the cutting edges of dactylus and fixed finger of the second pereiopod. The coloration in life of both species clearly discriminates one species from the other. The taxonomic status of some specimens previously reported as P. holthuisi is briefly discussed.

Animals↗
PubMed1977

Activity and physiological significance of the pleopods in the respiration of Callianassa californiensis (Dana) (Crustacea: Thalassinidea).

1. The pleopods of C. californiensis, a potential site for extrabranchial oxygen exchange, do not contribute significantly to oxygen consumption. 2. C. californiensis has a gill surface area of 4.13 +/- 0.72 cm2/g wet body weight, the lowest value yet reported for a totally aquatic crustacean. 3. C. californiensis, when placed in simulated burrow conditions, regulates the PO2 very loosely in its immediate microhabitat, using its pleopods. 4. Field studies of pH and PO2 values in burrows of C. californiensis indicate that animal movement may play a large part in water exchange between the surface and burrow. 5. Activity studies suggest that oxygen is not critical to C. californiensis on a short term basis. Perception of oxygen after long deprivation may signal the possibility of renewed feeding and activity at the surface of its burrow.

Animals↗
PubMed2002

Postembryonic eye growth in the seashore isopod Ligia exotica (Crustacea, Isopoda).

The eye of Ligia exotica is of the apposition type and has open rhabdoms. The facets are hexagonal, and the dioptric apparatus consists of a flat cornea and a spherical crystalline cone placed in the center of two large cone cells. Each ommatidium has seven regular retinula cells and one eccentric cell; a basement membrane forms the proximal boundary of the retina. With increases in body size from 0.6 to almost 4.0 cm, facet numbers and ommatidial diameters increased from 800 to 1500 and 35 microm to 100 microm, respectively; eye length and width grew from 1.2 to 3.2 and 0.9 to 2.5 mm, respectively; and length of dioptric apparatus and width of retinal layer changed from 70 microm to 180 microm and about 70 microm to 120 microm. Visual angles and interommatidial angles of centrally located ommatidia remained constant at about 30 and 6.9 degrees, respectively. An almost perfect linear relationship was found when eye length was plotted against the product between the square root of the total number of ommatidia and the ommatidial diameter. No difference between males and females was observed in any of the relationships, but the results suggest that, compared with smaller specimens, larger ones possess increased absolute sensitivity in single ommatidia, increased sensitivity to point sources, and overall larger angular visual fields for the eye in its totality. This means that larger individuals of L. exotica (which are also faster) have an advantage over smaller individuals at night, but that smaller individuals may cope better with bright lights. Vision in L. exotica seems useful not only in detecting potential danger, but also in locating and approaching cliffs from a distance of 2-4 m when swimming in seawater.

Animals↗
PubMed2001

Function and functional groupings of the complex mouth apparatus of the squat lobsters Munida sarsi Huus and M. tenuimana G.O. Sars (Crustacea: Decapoda).

Like all other decapods, the anomuran squat lobsters Munida sarsi and M. tenuimana have a mouth apparatus composed of six pairs of mouthparts plus labrum and paragnaths (upper and lower lips). To study the functional significance of this complexity, we examined the mouthparts with scanning electron microscopy and also observed their function directly, under laboratory conditions, using macro-video equipment. No differences were found between the two species. The movement patterns of the mouthparts are described in detail and illustrated as serial drawings. Proceeding from maxillipeds 3 towards the mandibles, the movement pattern gets increasingly stereotypical, with the mandibles performing but a single movement in a medio-lateral plane. From morphology, the mouthparts are subdivided into 20 parts, but from the functional analyses the 20 parts form 8 functional groups: 1, transporting mouthparts (maxilliped 2 endopod and maxilliped 3 endopod); 2, transporting-aligning mouthparts (maxilliped 1 basis); 3, sorting-aligning mouthparts (maxilla 1 basis and maxilla 2 basis); 4, current-generating mouthparts (flagella of maxilliped 2 and maxilliped 3 exopods); 5, cutting-crushing mouthparts (incisor and molar processes, labium, and mandibular palp); 6, ingesting mouthparts (maxilla 1 coxa, maxilla 2 coxa, and maxilliped 1 coxa); 7, respiratory mouthparts (scaphognathite, maxilliped 1 epipod, and maxilliped 2 and maxilliped 3 exopods); and 8, dorso-ventral mouthparts (maxilla 1 endopod, maxilla 2 endopod, maxilliped 1 endopod, and maxilliped 1 exopod). These groupings apply mostly to the processes of food handling and have little significance with respect to grooming. When comparing our results to the literature on other decapods, we found much resemblance to conditions in other anomurans.

Animals↗
PubMed2003

Role of maxilla 2 and its setae during feeding in the shrimp Palaemon adspersus (Crustacea: Decapoda).

The movements of the basis of maxilla 2 in Palaemon adspersus were examined using macro-video recordings, and the morphology of its setae was examined using both scanning and transmission electron microscopy. The basis of maxilla 2 performs stereotypical movements in the latero-medial plane and gently touches the food with a frequency of 3-5 Hz. The medial rim of the basis of maxilla 2 carries three types of seta. Type 1 is serrate, type 2 and 3 are serrulate, and type 2 has a prominent terminal pore. Type 2 is innervated by 18-25 sensory cells whose cilia protrude through the terminal pore and are in direct contact with the external environment. The structure of type 2 setae indicates that they are mainly gustatory, although still bimodal due to their innervation by presumed chemosensory and mechanosensory neurons. Distally, the three types of setae have a complex arrangement of the cuticle involving water-filled canals, which may serve to improve flexibility. Type 1 and 3 setae have fewer sensory cells (4-9) but probably also have a bimodal sensory function. The function of type 1 setae is probably to protect type 2 setae, while type 3 setae might serve to groom the ventral side of the basis of maxilla 1.

Animal Structures↗