Length Of Carpus Research Articles

Sexual dimorphism in the methane seep-dwelling Costa Rican yeti crab Kiwa puravida (Decapoda: Anomura: Kiwaidae)

Deep-sea chemosynthesis-based ecosystems support unique biological communities, but human impacts are an increasing threat. Understanding the life-history traits of species from deep-sea chemosynthesis-based ecosystems can help to develop adequate management strategies, as these can have impacts on ecological responses to changes in the environment. Here we examined the occurrence of sexual dimorphism in the yeti crab Kiwa puravida, an endemic species from the Costa Rican Pacific margin that aggregates at active methane seeps and depends on chemosynthetic bacteria for nutrition. The two morphological features examined included the claws, suspected to be under sexual selection and used for defense, and the carpus of the second pereopod not suspected to be under sexual selection. A total of 258 specimens, 161 males, 81 females, 16 juveniles, were collected from Mound 12 at 1,000-1,040 m depth in 2017 and 2018 and analyzed. We found that males have larger and wider claws than females, while there were no differences in carpus length. These results suggest that claw weaponry is under sexual selection in K. puravida, which is probably related to the mating system of this deep-sea species. This is the first attempt to study the reproductive biology of K. puravida, and additional observations will be necessary to shed more light on this matter.

Size Distribution, Length-Weight Relationship, and Size at Morphometric Maturity of the Mud Spiny Lobster Panulirus polyphagus (Herbst, 1793) in the Johor Strait

Spiny lobsters of the genusPanulirusare economically important and support local fishing communities. However, mud spiny lobsterPanulirus polyphagusis among the least known species within this genus in terms of their biological information. This study relates to the size distribution, length-weight relationship, and size at morphometric maturity ofP. polyphagusin the Johor Strait. Within the year 2010, 300 specimens were collected off the coast of Johor Strait, Malaysia. There was no significant difference in body size (cephalothorax length, CL) and body weight (BW) between sexes. CL and BW were highly correlated and males ofP. polyphagusdisplayed positive growth allometry, whereas the opposite was observed in females. Based on the merus (ML) and carpus length (CPL) of the third right walking leg, the piecewise linear regression analysis estimated that the size at maturity for male was 6.58 cm CL (based on ML) and 7.58 cm CL (based on CPL), whereas it was 8.18 cm CL (based on ML) and 6.75 cm (based on CPL) for females. Two discriminant functions of high classification and revalidation rates (> 98.6% in males and > 98.7% in females) that can discern maturation status in males and females ofP. polyphaguswere derived using the discriminant function analysis. Biological information derived from this study serves as an essential baseline for future fishery management and conservation ofP. polyphagus.

Resurfacing Capitate Pyrocarbon Implant Without Capitate Pole Resection to Improve Clinical Results in the Treatment of Chronic Wrist Arthritis.

Proximal row carpectomy (PRC) is a long-time, well-accepted, easy-to-reproduce procedure for the treatment of several painful degenerative conditions of the wrist, when capitate pole and radius lunate fossa are preserved. It has been reported to relieve pain and preserve a substantial wrist range of motion, although a partial loss of strength has to be expected because of the decreased length of the carpus. Since 2010, a new technique has been described in the literature using the resurfacing capitate pyrocarbon implant, combined with PRC. This implant has been designed to perform PRC even in the presence of degenerate joint surfaces, and thus resolves the limited indications of this procedure; however, if a resection of the capitate pole is performed to set up the implant, similar to PRC it may not positively influence the recovery of strength. The authors propose an resurfacing capitate pyrocarbon implant technique without any capitate bone resection, to preserve as much as possible the carpus length and so to improve the functional recovery. The surgical technique, is described in detail and preliminary results are discussed.

Taxonomic discrimination of species of the genus Metapenaeus Wood-Mason, 1891 from Indian waters through morphometric and molecular studies

Abstract The present study identified useful characters in the discrimination of species of the genus Metapenaeus, viz., Metapenaeus affinis, M. alcocki, M. brevicornis, M. dobsoni, M. kutchensis, M. monoceros and M. moyebi, in Indian waters, on the basis of morphometric and molecular studies. Out of 40 morphometric measurements, a correlation matrix of 14 morphometric measurements: carapace width, carapace depth, length of rostrum, of antennular peduncle, of telson, and of 6th abdominal somite; 6th abdominal somite depth, antennal scale length, merus length of 1st pereopod, movable finger length of 1st pereopod, movable finger length of 2nd pereopod, movable finger length of 3rd pereopod, merus length of 5th pereopod, and carpus length of 5th pereopod, were all found to be important in discriminating those seven species. The generated classification matrix showed 100% accurate classification of six species, except M. kutchensis (87.09%). DNA barcodes (588 bp) were generated for Metapenaeus brevicornis, M. dobsoni, M. ensis, M. kutchensis and M. monoceros. A simple identification key is thus proposed for nine species of Metapenaeus from Indian waters.

Male morphotypes of the freshwater prawn Macrobrachium brasiliense (Decapoda: Caridea: Palaemonidae)

AbstractSome decapod species have intraspecific morphological variations that result in distinct adult morphotypes that influence the population structure, social dominance, and reproduction of the population. Here we investigated whether this differentiation into morphotypes occurs in adult males of Macrobrachium brasiliense, through the analysis of relative growth and morphology. Specimens were collected in the region of Uberlândia, Minas Gerais state, southeastern Brazil. Seven dimensions of each male were measured: carapace length (CL), ischium length, merus length, carpus length, propodus length, dactylus length, and major cheliped length. Principal component analysis, clustering, and discriminant analyses were used to identify possible morphotypes. The analysis of relative growth was employed to estimate the growth patterns of body structures (dependent variables) in relation to the CL (independent variable). Two morphotypes were identified: Mirim, which has less developed chelipeds (23.31 ± 3.08 mm) with fewer spines, and Açu, which has larger chelipeds (41.39 ± 8.14 mm) with many well‐developed spines, especially in the merus. Most morphometric relationships differed significantly (p < .01) between the two morphotypes. The chelipeds were useful characters for the identification of the morphotypes of M. brasiliense, corroborating previous descriptions of the genus. We provide a detailed description of the main macroscopic characteristics that differed between morphotypes, which will enable their identification in future studies. Our results contribute to the knowledge of the population biology of M. brasiliense and should be considered in future investigations, since the presence of these male morphotypes probably influences the reproductive biology and population ecology of the species.

Relative growth, sexual maturity and handedness in the ghost shrimp <em>Callichirus major</em> (Decapoda: Callianassidae) from the southwestern Atlantic

Biometric studies provide valuable information about changes associated with the growth and sexual maturity of living organisms. We analysed sexual dimorphism, allometric growth, sexual maturity and handedness in the ghost shrimp Callichirus major at Gonzaga beach, Brazil, where the catches of this species have been prohibited since 1992. To this end, a total of 544 individuals of C. major were collected during 12 months of sampling. Males were significantly smaller than females, denoting sexual dimorphism with respect to body size. The analysis of allometric growth between chelar carpus length and carapace length (CL) revealed a positive allometric relationship in juveniles of both sexes and adult males, but a negative allometry in adult females. Overall, our results showed the existence of two main growth phases related to sexual maturity, with a similar transition point for males (15.0 mm CL) and females (16.0 mm CL). Heterochely and homochely were registered in shrimp from both sexes, but in males heterochely occurred to a higher degree and was predominant (86.9%), whereas in females homochely was slightly more frequent (59.3%). The consequences of sexual dimorphism in terms of body size and chelipeds in the mating system of C. major are discussed in this study.

A new species of the genus Elasmopus from Miyako Island, Japan (Crustacea: Amphipoda: Maeridae).

A new species of the maerid amphipod, Elasmopus nkjaf, from Miyako Island, Ryukyu Islands, Japan, is named and described. Additionally, nucleotide sequences of nuclear 28S ribosomal RNA and histone H3 as well as mitochondrial cytochrome c oxidase subunit I and 16S ribosomal RNA from its holotype and paratype were determined. Elasmopus nkjaf sp. nov. belongs to the rapax-group, and distinguished from the other rapax-group species by long setae on ventral margin of epimeral plate 3, gland cone of peduncular article 2 of antenna 2 not reaching to end of peduncular article 3, propodus of gnathopod 1 facially setose, length of propodus of male gnathopod 2 shorter than 3 times as long as length of carpus, medial face of propodus of male gnathopod 2 shallowly hollowed, posterior margin of epimeral plate 3 without denticles. A key to the species of Elasmopus species occurring Japanese and adjacent waters is provided.

Social structure, sexual dimorphism and relative growth in the ghost shrimp Callichirus seilacheri (Bott, 1955) (Decapoda, Axiidea, Callianassidae) from the tropical eastern Pacific

ABSTRACTWe analyzed the social structure, sexual dimorphism and relative growth in the burrowing shrimp Callichirus seilacheri from the tropical eastern Pacific. To this end, 456 individuals of C. seilacheri were collected during monthly sampling from December 2011 to November 2012. No shrimp pairs or burrows inhabited by more than one shrimp were detected during the study period. Males were significantly smaller than females, denoting sexual dimorphism with respect to body size. In many juvenile males and females, the size of the right and left claws was the same, whereas in others the largest cheliped was located on the right or left side. Analysis of allometric growth between cheliped carpus length and cephalothorax length revealed an isometric relationship in juveniles of both sexes and adult females and positive allometric growth in adult males. The adjustment of the above relationship by the Somerton's method, denoted the existence of two main phases of growth related to sexual maturity, with transition points between juvenile and adult phase at 12.3 mm and 12.0 mm of body size for males and females, respectively. The observations on social structure, sexual dimorphism and relative growth of C. seilacheri argued that this species is polygamous. Furthermore, the high frequency of solitary females found brooding embryos suggested that males might roam among galleries in search of receptive females.

Relative growth and morphological sexual maturity of the caridean shrimp Nematopalaemon schmitti (Decapoda: Caridea: Palaemonidae) in an upwelling region in the Western Atlantic

In crustaceans, successful reproductive processes, such as the transition from juvenile to adult, exhibit important morphological changes that can be detected by analyzing relative growth. This study describes the relative growth of body structures in Nematopalaemon schmitti and its secondary sexual characteristics, and also estimates the morphological sexual maturity of this species in a region influenced by upwelling. The carapace length (CL), second pleuron length (PlL), cheliped carpus length (CaL), cheliped propodus length (PrL) and the length of appendix masculina (AML) of the shrimp were measured. The relationships that best demonstrated the changes in allometric coefficient between demographic categories were AML vs. CL for males, and PlL vs. CL for females. The estimated CL for morphological sexual maturity in males was 8.51 mm and 9.30 in females. Our results showed the appendix masculine and the second pleuron were secondary sexual characteristics that play roles in reaching the morphological sexual maturity necessary for reproductive success and to assure the life cycle of this species.

Variation in Morphometric Characters in Four Sand Crab (Albunea symmysta) Populations Collected from Sumatra and Java Island, Indonesia.

Variation in morphometric characters in four sand crab (Albunea symmysta) populations from four intertidal areas in Sumatra (Aceh and Bengkulu) and Java (Cilacap and Yogyakarta) were studied. Crabs collected from the four sites were measured to obtain 10 morphometric characters, i.e., carapace length (CL), carapace width (CW), ocular peduncle length and width (LOP and WOP), telson length and width (LT and WT), merus length (ML), carpus length (CaL), propodus length (PL), and dactylus length (DL). Allometric relationships were established among three morphometric characters (CW, PL, and DL) for each site, in which CL was fixed on the abscissa as a reference variable. The analysis of covariance showed that population from Yogyakarta had a greater carapace width and the Aceh population had a longer dactylus length. In terms of propodus length, the Aceh population had a longer dactylus length than the Bengkulu population. Two group populations were detected by cluster analysis with 10 morphometric characters, i.e., the Sumatra population and the Java population.

Standardized quantitative measurements of wrist cartilage in healthy humans using 3T magnetic resonance imaging.

To quantify the wrist cartilage cross-sectional area in humans from a 3D magnetic resonance imaging (MRI) dataset and to assess the corresponding reproducibility. The study was conducted in 14 healthy volunteers (6 females and 8 males) between 30 and 58 years old and devoid of articular pain. Subjects were asked to lie down in the supine position with the right hand positioned above the pelvic region on top of a home-built rigid platform attached to the scanner bed. The wrist was wrapped with a flexible surface coil. MRI investigations were performed at 3T (Verio-Siemens) using volume interpolated breath hold examination (VIBE) and dual echo steady state (DESS) MRI sequences. Cartilage cross sectional area (CSA) was measured on a slice of interest selected from a 3D dataset of the entire carpus and metacarpal-phalangeal areas on the basis of anatomical criteria using conventional image processing radiology software. Cartilage cross-sectional areas between opposite bones in the carpal region were manually selected and quantified using a thresholding method. Cartilage CSA measurements performed on a selected predefined slice were 292.4 ± 39 mm(2) using the VIBE sequence and slightly lower, 270.4 ± 50.6 mm(2), with the DESS sequence. The inter (14.1%) and intra (2.4%) subject variability was similar for both MRI methods. The coefficients of variation computed for the repeated measurements were also comparable for the VIBE (2.4%) and the DESS (4.8%) sequences. The carpus length averaged over the group was 37.5 ± 2.8 mm with a 7.45% between-subjects coefficient of variation. Of note, wrist cartilage CSA measured with either the VIBE or the DESS sequences was linearly related to the carpal bone length. The variability between subjects was significantly reduced to 8.4% when the CSA was normalized with respect to the carpal bone length. The ratio between wrist cartilage CSA and carpal bone length is a highly reproducible standardized measurement which normalizes the natural diversity between individuals.

Ocurrence of male morphotypes of Macrobrachium amazonicum (Caridea, Palaemonidae) in a population with an entirely freshwater life cycle

This study records, for the first time, the occurrence of all four male morphotypes in a population of Macrobrachium amazonicum from a continental environment, with an entirely freshwater life cycle. The specimens studied came from the Tietê River, state of São Paulo, Brazil, and were collected in a lotic environment downstream from Ibitinga Dam. This population was compared with other continental populations, including a population from the dam itself, collected in a previous study. Four samples of 30 minutes were taken monthly, using a trap, from January to April 2011. Each male specimen was measured with respect to seven body dimensions as follows: carapace length (CL), right cheliped length (RCL), dactyl length (DCL), propodus length (PPL), carpus length (CRL), merus length (ML) and ischium length (IL). The relative growth was analyzed based on the change in growth patterns of certain body parts in relation to the independent variable CL. The four male morphotypes proposed for the species were found using morphological and morphometric analyses. Different biological characteristics were found between the populations studied. The male population of the lake of Ibitinga and from Pantanal presented mean sizes and number of morphotypes lower than the population studied here. These differences seem to be closely related to ecological characteristics of the environments inhabited by these populations. Our results supported the hypothesis that coastal and continental populations of M. amazonicum belong to the same species.

Four species of the genus Stephonyx (Crustacea: Amphipoda: Uristidae) from Japan, with description of a new species

Four species including one new species of the genus Stephonyx are described from Japan: Stephonyx perexcavatus sp. nov., Stephonyx biscayensis (Chevreux, 1908), Stephonyx laqueus (Barnard, 1967) and Stephonyx mytilus (Barnard and Ingram, 1990). Stephonyx perexcavatus sp. nov. is distinguished from the congeners by the combination of the following features: dorsal margin of body smooth, posteroventral corner of epimeral plate 1 not pointed, lateral cephalic lobe rounded, article 1 of mandibular palp shorter than 0.5 times article 2, length of carpus of gnathopod 1 longer than 0.75 times propodus, and palm of gnathopod 2 deeply concave. This is the first record of S. biscayensis and S. mytilus from Japan. A key to the species of Stephonyx is provided.

Reports of Galathea Fabricius, 1793 (Crustacea: Decapoda: Anomura: Galatheidae) from Chinese waters, with descriptions of two new species

Eighteen species of the galatheid genus Galathea Fabricius, 1793 from Chinese waters are reported in the present paper based on material in the collection of the Marine Biological Museum (MBM) in the Institute of Oceanology, Chinese Academy of Sciences, Qingdao (IOCAS), including two new species (G. babai n. sp., G. sinensis n. sp.) and eight species new to Chinese waters (G. anepipoda Baba, 1990, G. consobrina De Man, 1902, G. coralliophilus Baba & Oh, 1990, G. guttata Osawa, 2004, G. inconspicua Henderson, 1885, G. pilosa De Man, 1888, G. ternatensis De Man, 1902, and G. whiteleggii Grant & McCulloch, 1906). Galathea babai n. sp. can be distinguished from all the other congeneric species by the presence of a strong median protogastric spine. Galathea sinensis is distinguished from its nearest congener, G. multilineata, by having more numerous transverse striae on the carapace, the lateral margin of the carapace with only one instead of four spines behind the posterior cervical groove, the P1 fingers distally ending in incurved spines that cross when occluded (instead of being spooned), and a much shorter cheliped (especially the carpus length relative to breadth). To date, 26 species of Galathea Fabricius, 1793 have been recorded from Chinese waters, including the two new species.

Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 12

Manente and coll. have recently developed an innovative soft hand brace called Manu for conservative treatment of Carpal Tunnel Syndrome (CTS); a randomised controlled study showed that this hand brace, if worn at night for one month, is highly efficient in relieving symptoms and functional loss in CTS patients. This study aims at evaluating, through Magnetic Resonance Imaging (MRI), the changes of carpal tunnel in CTS patients and controls wearing Manu, the innovative soft hand brace for CTS. Thirteen subjects (9 with CTS and 4 controls) were enrolled in the study. T1 and STIR sequences were performed using a 0.2 T E‐Scan. Some morphologic parameters (tunnel diameters and area, carpus length and nerve signal intensity) were measured at three different scanning levels. Evaluation was carried out before and after the application of the brace. Remarkable differences were recorded in the measurements performed before and after the application of the brace, particularly in the constant increase of front‐rear diameter and tunnel shape rounding. These data could explain the lighter symptoms after using the brace. The Manu hand brace increased the carpal tunnel front‐rear diameter rounding the tunnel shape, hence the clinical efficacy in CTS.