Sexual dimorphism and allometry in the giant water strider Gigantometra gigas

1999 ◽  
Vol 77 (6) ◽  
pp. 923-929 ◽  
Author(s):  
Michelle Tseng ◽  
Locke Rowe
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Body Length ◽  
Total Body Length ◽  
Correlated Response ◽  
Water Strider ◽  
Leg Length ◽  
Allometric Analysis ◽  
Total Leg ◽  
Total Body

This study describes sexual dimorphism in size (total body length and lengths of leg components) and in the allometric relationships between leg-component lengths and total body length in the giant water strider Gigantometra gigas (Heteroptera: Gerridae). Gigantometra gigas is the largest known gerrid, and has been previously described as monomorphic for body size. We compare our results with analogous data collected on Gerris buenoi, a species of more moderate size, where females are larger than males. Based on 94 specimens of G. gigas, we conclude that males are larger than females in all measured traits. This dimorphism was most spectacular in the leg components, which are 10-50% longer in males than in females. Males are generally more variable in size than females, and this is especially so for leg components. Allometric analysis suggests that total leg lengths (particularly middle and rear) increase at a much greater rate with body size in males than in females, therefore there is sexual dimorphism in allometries on the scale of that in the traits themselves. The relationship between middle and hind leg lengths is strong in both sexes, and appears to differ very little between the sexes or between G. gigas, and Ge. buenoi. These data suggest a constraint on this relationship, perhaps because of the biomechanics of locomotion. We propose that sexual selection acting on middle leg lengths in males explains both the increase and variance in middle leg length, and that hind leg length follows by correlated response.

scholarly journals Sexual Dimorphism in Anthonomus santacruzi (Coleoptera: Curculionidae): a Biological Control Agent of Solanum mauritianum Scopoli (Solanaceae)

2020 ◽  
Vol 49 (6) ◽  
pp. 840-850
Author(s):  
Archbold Sasa ◽  
Rafał Gosik ◽  
Ed T. F. Witkowski ◽  
Marcus J. Byrne ◽  
Miłosz A. Mazur
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Body Length ◽  
Biological Control Agent ◽  
Abdominal Tergite ◽  
Total Body Length ◽  
The Body ◽  
Body Structure ◽  
Solanum Mauritianum ◽  
Total Body

AbstractThere is evident variation in body size amongst Anthonomus santacruzi Hustache, 1924, weevils. The aims of this study were to assess if the variation in body size in A. santacruzi weevils is a result of sexual dimorphism and what features can be used to distinguish males from females. The weevils were collected from field sites in Mpumalanga, South Africa, where they were introduced as biocontrol agents of Solanum mauritianum Scopoli. Body structures and the presence/absence of the tergal notch was examined under an optical stereomicroscope and SEM to assess differences between sexes. The morphometric analysis of the body structures included rostrum length (base–apex and antennal insertion–apex), elytral length and width, pronotum length and width, first tarsus length, first tibia length, funiculus length and total body length. Rostrum length, elytra length and width and total body length were significantly larger in females than in males. A tergal notch in the 8th abdominal tergite was present in males and absent in females. The body structure; of rostrum length, elytra length and width and total body length overlapped between sexes in some specimens. The abdominal tergal notch was found to be the most useful body structure to distinguish males from females in A. santacruzi.

scholarly journals PENGUKURAN PANJANG TUBUH CACING NIPAH PENDEK Namalycastis abiuma (POLYCHAETA: NEREDIDAE) DARI PERAIRAN MANGROVE SUNGAI KAPUAS KALIMANTAN BARAT

2018 ◽  
Vol 11 (2) ◽  
pp. 183-189
Author(s):  
Junardi Junardi
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Body Length ◽  
Anterior Segment ◽  
Total Body Length ◽  
The Body ◽  
Female Body Size ◽  
Alternative Approach ◽  
Total Body ◽  
The Relationship

AbstrakCacing Nipah Pendek Namalycastis abiuma memiliki tubuh yang elastis dan mudah putus sehingga diperlukan pendekatan morfometri tubuh lain untuk menentukan panjang tubuh sesungguhnya. Tujuan penelitian ini untuk menentukan panjang tubuh total cacing nipah pendek dengan menggunakan bobot tubuh, jumlah total segmen berseta, panjang tiga segmen anterior pertama (L3) dan lebar segmen berseta atau setiger ke-10 (S-10). Spesimen yang digunakan dipilih hanya individu yang lengkap dan utuh. Pengukuran dilakukan dibawah mikroskop dengan lensa okular yang dilengkapi dengan mikrometer. Data dianalisis dengan analisis korelasi. Cacing yang digunakan sebanyak 258 individu yang terdiri atas 190 immature, 54 submature dan 14 mature dengan ukuran panjang tubuh rata-rata berturut-turut 108,62±34,80 mm, 172,27±42,78 mm dan 123,14±57,40 mm. Cacing betina ditemukan memiliki ukuran tubuh lebih besar dari jantan. Panjang tubuh N. abiuma dapat diduga dengan bobot tubuh, panjang L3 dan lebar S-10 dengan nilai koefisien korelasi (r) berturut-turut 0,82, 0,73 dan 0,78. Pendekatan morfometri dapat digunakan untuk menentukan ukuran tubuh N. abiuma.Abstract The short nypa palm worm Namalycastis abiuma has an elastic and fragile body. Therefore, an alternative approach of morphometrical techniques is needed to determine the total body length. This research aimed to estimate the total body length of the short nypa palm worm based on body weight, the total number of segments, the length of the first three anterior segment (L3) and the tenth setiger width (S10). Body measurement was done using stereomicroscope fitted with the micrometer. Correlation analysis was done to describe the relationship between the length of L3 and the width of S10. A total of 258 complete and whole specimens consisted of 190 immature, 54 submature, and 14 mature individuals. The average body length of immature individuals was 108.62±34.80 mm, 172.27±42.78 mm for sub mature individuals, and 123.14±57.40 mm for mature individuals. Based on sexual dimorphism, the female body size is larger than male. The body length of N. abiuma can be estimated by body weight, the length of L3, and the  width of S10, with  correlation coefficient (r) of 0.82, 0.73 and 0.78, respectively. Morphometry approach can be used to determine the body size of N. abiuma. 

scholarly journals The vulnerability of species to range expansions by predators can be predicted using historical species associations and body size

2015 ◽  
Vol 282 (1812) ◽  
pp. 20151211 ◽  
Author(s):  
Karen M. Alofs ◽  
Donald A. Jackson
Keyword(s):  
Climate Change ◽  
Body Size ◽  
Body Length ◽  
Species Interactions ◽  
Environmental Changes ◽  
Regional Scale ◽  
Total Body Length ◽  
Relative Impact ◽  
Total Body ◽  
Historical Range

Climate change threatens species directly through environmental changes and indirectly through its effects on species interactions. We need tools to predict which species are most vulnerable to these threats. Pairwise species associations and body size are simple but promising predictors of the relative impact of species introduced outside of their historical ranges. We examined the vulnerability of 30 fish species to the impacts of three centrarchid predators that are being introduced to lakes north of their historical range boundaries. Species that were negatively associated with each centrarchid in their historical range were more likely to be lost from lakes with centrarchid introductions. Total body length was most important in predicting impact for the most gape-limited predator. At the regional scale, our method identifies those species most vulnerable to introductions facilitated by climate change and can easily be applied to a range of taxa undergoing range expansions.

The Body-Length-Leg Ratio in the General Population and in Mental Hospital Patients and its Possible Significance in Suicide

1936 ◽  
Vol 82 (336) ◽  
pp. 38-42 ◽  
Author(s):  
H. Pullar Strecker
Keyword(s):  
General Population ◽  
Body Length ◽  
Mental Hospital ◽  
Total Body Length ◽  
The Body ◽  
Leg Length ◽  
Hospital Patients ◽  
Preliminary Communication ◽  
Total Body ◽  
Very High

Psychiatrists will welcome Piney's recent preliminary communication (1) on the possible significance of certain physical characters. A series of measurements of about 500 bodies revealed that a very high number of suicides among the general population occurred in persons showing a body-length-leg ratio of over 50, i. e., the leg-length being more than 50% of the total body-length. Piney believes that persons of this type, among other abnormalities, have such mental characters as may lead to suicide. He raises the question whether body-length-leg ratios of over 50 are commoner among the inmates of mental hospitals than in the general population.

Reflecting materials in the eyes of three teleosts, Orthopristes chrysopterus, Dorosoma cepedianum and Anchoa mitchilli

1973 ◽  
Vol 184 (1074) ◽  
pp. 15-27 ◽  
Keyword(s):  
Body Length ◽  
Pigment Epithelium ◽  
Total Body Length ◽  
Gizzard Shad ◽  
Dorosoma Cepedianum ◽  
Anchoa Mitchilli ◽  
First Report ◽  
Total Body ◽  
Bay Anchovy

The tapeta lucida of three species of teleosts were examined to determine the composition of the reflecting material. The fishes were bay anchovy Anchoa mitchilli (Engraulidae), gizzard shad Dorosoma cepedianum (Clupeidae) and pigfish Orthopristes chrysopterus (Haemulidae). The tapetum of each species was situated in the pigment epithelium of the eye. That of the pigfish contained triglycerides identified as chiefly glyceryl tridocosahexaenoate. A reduced pteridine, 7, 8-dihydroxanthopterin, occurred in the tapetum of the gizzard shad. Guanine occurred in the tapetum of the bay anchovy. The tapetum of the shad contained brightly reflecting particles about 0.5 μm in diameter There were 10.8 mg of dihydroxanthopterin in the tapetum of a shad (total body length 23 cm) and 0.46 mg of guanine in the tapetum of an anchovy (total body length 9 cm). This is the first report of a pteridine acting as a retinal reflector in vertebrates. Various aspects of retinal reflectors of teleosts are discussed and their variety and common characteristics commented upon.

Steinernema loci sp. n. and Steinernema thanhi sp. n. (Rhabditida: Steinernematidae) from Vietnam

Nematology ◽  
2001 ◽  
Vol 3 (6) ◽  
pp. 503-514 ◽  
Author(s):  
Maurice Moens ◽  
Ngoc Chau Nguyen ◽  
Ke Long Phan
Keyword(s):  
Body Length ◽  
First Generation ◽  
Tail Length ◽  
Total Body Length ◽  
Body Width ◽  
Lateral Field ◽  
Diagnostic Characters ◽  
Spicule Length ◽  
Third Stage ◽  
Total Body

AbstractTwo new species of Steinernema (Rhabditida), Steinernema loci sp. n. and S. thanhi sp. n., were isolated from beach soil in Thanhhoa and Hatinh provinces in the northern part of Vietnam. A combination of morphological, morphometric and rDNA-RFLP features indicated the distinctness of both species from other Steinernema spp. Diagnostic characters of Steinernema loci sp. n. include: total body length (896-1072 μm), distance from anterior end to excretory pore (EP = 71-86 μm), tail length (66-83 μm), lateral field in mid-body with eight ridges (nine distinct lines) and rounded, broad and smooth anterior end of the third stage infective juvenile; first generation males were characterised by body width, spicule length and the ratio spicule length : anal body width (SW). Diagnostic characters of Steinernema thanhi sp. n. third stage infective juveniles include: total body length (720-960 μm), EP (68-84 μm), tail length (52-72 μm), lateral field in mid-body with eight ridges (nine distinct lines) and rounded, broad and smooth anterior end. Spicule length, ratio SW and arrangement of genital papillae characterised the first generation males.

scholarly journals Variation in body size of Phanocerus clavicornis Sharp, 1882 (Coleoptera: Elmidae: Larainae) in Atlantic Rainforest streams in response to hydraulic disturbance

2013 ◽  
Vol 73 (4) ◽  
pp. 747-752 ◽  
Author(s):  
MO. Segura ◽  
T. Siqueira ◽  
AA. Fonseca-Gessner
Keyword(s):  
Body Size ◽  
Total Body Length ◽  
Atlantic Rainforest ◽  
Southeastern Brazil ◽  
Head Width ◽  
High Plasticity ◽  
Larval Size ◽  
Morphometric Variation ◽  
Total Body ◽  
Rain Events

In this study, patterns of body size of Phanocerus clavicornis Sharp, 1882 (Coleoptera: Elmidae: Larainae) were investigated along a gradient of change in speed of flow conditions in streams of low order in the Atlantic Rainforest in southeastern Brazil. Specifically, the hypothesis that the distribution of P. clavicornis larvae vary in size in response to variations in the speed of flow in streams was tested. A Surber sampler was used to collect larvae from the streambed during two sampling periods, defined by the rain regime: August in the dry season and February in the rainy season. Possible differences in mean measured body size were tested by analysis of variance (ANOVA). The ANOVA result indicated for all measurements on the larvae collected in first-order streams (head width, prothoracic width and total body length), there were significant differences indicating a morphometric variation due to changing hydraulic conditions, the smallest larvae being associated with the period of greater rainfall. However, the larger streams (3rd order), where the rain events had less impact on the larval size, varied widely. The results of this study suggest that the interstitial space is important for the protection of the larvae from water flow, and that populations of P. clavicornis have high plasticity, a key feature for the occupation of unstable environments for this species. These results are important for an understanding of the life history and behavioural characteristics of the species, which allow them to persist in streams along a gradient of flow disturbance.

Kroyeria caseyi sp.nov. (Kroyeriidae: Siphonostomatoida), a parasitic copepod infesting gills of night sharks (Carcharhinus signatus (Poey, 1868)) in the western North Atlantic

1986 ◽  
Vol 64 (11) ◽  
pp. 2492-2498 ◽  
Author(s):  
George W. Benz ◽  
Gregory B. Deets
Keyword(s):  
Body Length ◽  
North Atlantic ◽  
Total Body Length ◽  
Parasitic Copepod ◽  
Male And Female ◽  
Genital Complex ◽  
Total Body

Kroyeria caseyi sp.nov. (Kroyeriidae: Siphonostomatoida) is described from male and female specimens collected from gills of night sharks (Carcharhinus signatus (Poey, 1868)) captured in the western North Atlantic. Kroyeria caseyi is the only known member of the Kroyeriidae that is a mesoparasite, females being found partially embedded in the interbranchial septa of their hosts. Kroyeria caseyi is easily distinguished from other Kroyeria species by the armature of its swimming legs. Additionally, the genital complex of female K. caseyi is extremely long, composing up to 96% of the total body length. With some females reaching over 6 cm long, K. caseyi dwarfs all known congeners. First-stage nauplii collected from ruptured egg sacs are also described.

Nematodes of the order Dorylaimida from Romania. The genus Enchodelus Thorne, 1939. 3. Species with rounded tail and long odontostyle

Nematology ◽  
2010 ◽  
Vol 12 (4) ◽  
pp. 609-618 ◽  
Author(s):  
Marcel Ciobanu ◽  
Iuliana Popovici ◽  
Pablo Guerrero ◽  
Reyes Peña-Santiago
Keyword(s):  
Body Length ◽  
Additional Data ◽  
Cell Mass ◽  
Total Body Length ◽  
Genital System ◽  
Neck Length ◽  
Female Tail ◽  
Female Genital System ◽  
Total Body ◽  
Female Genital

Abstract Three species of the genus Enchodelus, one new and two known, from natural areas in Romania are studied. Enchodelus carpaticus sp. n. is distinguished by its body 1.59-1.87 mm long, lip region offset by a marked depression and 17-20 μm diam., odontostyle 39.5-47 μm long and 2.1-2.5 lip region diam. or 2.3-2.8% of total body length, odontophore 42-51 μm long and with distinct basal flanges, neck 336-388 μm long, pharyngeal expansion 136-167 μm long or 39-45% of total neck length, presence of dorsal cell mass near cardia, female genital system amphidelphic, uterus tripartite and 144-195 μm long or 2.2-2.9 times the corresponding body diam., pars refringens vaginae with two trapezoidal sclerotisations, V = 42-50, and female tail short and rounded (21-29 μm long, c = 55-87, c′ = 0.5-0.7). Additional data, including LM pictures, are presented for E. macrodorus and E. saxifragae.

scholarly journals Gill infection of Leporinus macrocephalus Garavello & Britski, 1988 (Osteichthyes: Anostomidae) by Henneguya leporinicola n. sp. (Myxozoa: Myxobolidae). Description, histopathology and treatment

1999 ◽  
Vol 59 (3) ◽  
pp. 527-534 ◽  
Author(s):  
M. L. MARTINS ◽  
V. N. de SOUZA ◽  
J. R. E de MORAES ◽  
F. R de MORAES
Keyword(s):  
Body Length ◽  
Body Surface ◽  
Total Body Length ◽  
Goblet Cells ◽  
Epithelial Hyperplasia ◽  
Daily Mortality ◽  
Secondary Lamellae ◽  
Gill Filaments ◽  
Total Body ◽  
Tissue Alterations

Piauçus (Leporinus macrocephalus), were raised in 300 m² ponds (density of 10 fish/m²) presenting asphyxia signals and daily mortality of 27 fishes. Specimens with 8-cm total body length, were collected for necropsy. Mucus of body surface and pieces of organs were collected and examined microscopically, in wet mounts, stained or in histological sections. The smears examination showed the presence of several spores in the secondary lamellae of the gill filaments, identified as Henneguya leporinicola n.sp (Myxozoa: Myxobolidae). Histopatological study showed epithelial hyperplasia and fulfilling of the spaces between the secondary lamellae, congestion and teleangiectasia sinusoidal. It was also observed hyperplasia of the goblet cells and several cysts of parasite with 70.3mum diameter. Such cysts were situated among the secondary lamellae, covered or not by the hyperplasic epithelium. With this diagnostic, three applications of formalin solution 10 ml/m³ were carried out. Fifteen days after that, fish were examined again to ascertain whether the treatment was efficient on disease caused by the protozoa. The tissue alterations present in the gills after the treatment were just a moderate sinusoidal congestion and a slight epithelial hyperplasia on the base of the secondary lamellae.

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