External features and life cycle of Cucumaricola notabilis nov.gen. et sp., a copepod parasite of the holothurian, Cucumaria

Parasitology ◽  
1958 ◽  
Vol 48 (3-4) ◽  
pp. 269-290 ◽  
Author(s):  
Nellie F. Paterson
Keyword(s):  
Systematic Position ◽  
Sexually Dimorphic ◽  
New Genus And Species ◽  
Cape Peninsula ◽  
Short Period ◽  
Copepodid Stage ◽  
Males And Females ◽  
Living Material ◽  
Copepod Parasites ◽  
Active Swimming

1. Cucumaricola notabilis, a new genus and species of Copepoda, occurs in cysts in the coelom of Cucumaria frauenfeldi Ludwig collected at Sea Point, Blaauwberg Strand and Dalebrook in the Cape Peninsula.2. An account is given of the features of the sexually dimorphic males and females.3. Fertilized eggs and nauplius larvae are also contained in the cysts and, from observations on living material, it has been established that, after escaping from the cysts, the larvae metamorphose within a short period into the copepodid stage. There are two copepodid stages, the first an active swimming form and the second a quiescent phase from which the juvenile parasite develops.4. Although of uncertain systematic position, this parasite seems to be nearly related to the Chondracanthidae. This conclusion is based on the similarity of the trunk appendages of the adult female to those of Acanthochondria as described by Oakley (1930), and also on the general agreement of the ontogeny with that of Acanthochondria cornuta investigated by Heegaard in 1947. It is further suggested that it may be assigned to the key devised by Delamare Deboutteville & Nunes-Ruivo (1955) for certain copepod parasites having some affinity with the Chondracanthidae.

Sex differences in melanotic encapsulation responses (immunocompetence) in the damselfly Lestes forcipatus Rambur

2002 ◽  
Vol 80 (9) ◽  
pp. 1578-1583 ◽  
Author(s):  
Christopher P Yourth ◽  
Mark R Forbes ◽  
Robert L Baker
Keyword(s):  
Sex Differences ◽  
Immune Responses ◽  
Life Histories ◽  
Mass Gain ◽  
Sexually Dimorphic ◽  
Foreign Objects ◽  
Males And Females ◽  
And Gender ◽  
Parasitic Mites ◽  
Melanotic Encapsulation

A few studies have shown that male and female invertebrates differ in immunity and that these differences appear related to differences in sexual dimorphism and gender differences in life histories. Melanotic encapsulation of foreign objects in insects is one form of immunity. The damselfly Lestes forcipatus Rambur is moderately sexually dimorphic, and much is known about patterns of mass gain in congeners relating to differences in life history between males and females. In this study, females were more immunoresponsive than males under controlled temperatures, following emergence, and at a time when parasitic mites were challenging these hosts. However, males and females that overlapped in mass at emergence did not differ in their immune responses. Males in better condition at emergence were more immunoresponsive than lighter males, but this relation was not found in females. Sex differences in immune expression may have implications for how females versus males are able to deal with challenges from parasites, under varying environmental conditions.

scholarly journals Heightened condition dependent expression of structural colouration in the faces, but not wings, of male and female flies

2021 ◽  
Author(s):  
Thomas E White ◽  
Amy Locke ◽  
Tanya Latty
Keyword(s):  
Mate Choice ◽  
Condition Dependence ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Honest Signals ◽  
Mutual Mate Choice ◽  
Close Range ◽  
Males And Females ◽  
Structural Colouration

Abstract Structurally coloured sexual signals are a conspicuous and widespread class of ornament used in mate choice, though the extent to which they encode information on the quality of their bearers is not fully resolved. Theory predicts that signalling traits under strong sexual selection as honest indicators should evolve to be more developmentally integrated and exaggerated than nonsexual traits, thereby leading to heightened condition dependence. Here we test this prediction through examination of the sexually dimorphic faces and wings of the cursorial fly Lispe cana. Males and females possess structural UV-white and golden faces, respectively, and males present their faces and wings to females during close-range, ground-based courtship displays, thereby creating the opportunity for mutual inspection. Across a field-collected sample of individuals, we found that the appearance of the faces of both sexes scaled positively with individual condition, though along separate axes. Males in better condition expressed brighter faces as modelled according to conspecific flies, whereas condition scaled with facial saturation in females. We found no such relationships for their wing interference pattern nor abdomens, with the latter included as a nonsexual control. Our results suggest that the structurally coloured faces, but not the iridescent wings, of male and female Lispe cana are reliable guides to individual quality and support the broader potential for structural colours as honest signals. They also highlight the potential for mutual mate choice in this system, while arguing for one of several alternate signalling roles for wing interferences patterns among the myriad taxa which bear them.

scholarly journals Sex identification in embryos and adults of Darwin’s finches

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0237687
Author(s):  
Mariya P. Dobreva ◽  
Joshua G. Lynton-Jenkins ◽  
Jaime A. Chaves ◽  
Masayoshi Tokita ◽  
Camille Bonneaud ◽  
...  
Keyword(s):  
Field Studies ◽  
Sexually Dimorphic ◽  
Genetic Studies ◽  
Darwin's Finches ◽  
Darwin’S Finches ◽  
Specific Morphology ◽  
Males And Females ◽  
Primer Sets ◽  
Dimorphic Species ◽  
Source Of Error

Darwin’s finches are an iconic example of adaptive radiation and evolution under natural selection. Comparative genetic studies using embryos of Darwin’s finches have shed light on the possible evolutionary processes underlying the speciation of this clade. Molecular identification of the sex of embryonic samples is important for such studies, where this information often cannot be inferred otherwise. We tested a fast and simple chicken embryo protocol to extract DNA from Darwin’s finch embryos. In addition, we applied minor modifications to two of the previously reported PCR primer sets for CHD1, a gene used for sexing adult passerine birds. The sex of all 29 tested embryos of six species of Darwin’s finches was determined successfully by PCR, using both primer sets. Next to embryos, hatchlings and fledglings are also impossible to distinguish visually. This extends to juveniles of sexually dimorphic species which are yet to moult in adult-like plumage and beak colouration. Furthermore, four species of Darwin’s finches are monomorphic, males and females looking alike. Therefore, sex assessment in the field can be a source of error, especially with respect to juveniles and mature monomorphic birds outside of the mating season. We caught 567 juveniles and adults belonging to six species of Darwin’s finches and only 44% had unambiguous sex-specific morphology. We sexed 363 birds by PCR: individuals sexed based on marginal sex specific morphological traits; and birds which were impossible to classify in the field. PCR revealed that for birds with marginal sex specific traits, sexing in the field produced a 13% error rate. This demonstrates that PCR based sexing can improve field studies on Darwin’s finches, especially when individuals with unclear sex-related morphology are involved. The protocols used here provide an easy and reliable way to sex Darwin’s finches throughout ontogeny, from embryos to adults.

scholarly journals Sex Differences in Exercise-Induced Bronchoconstriction in Athletes: A Systematic Review and Meta-Analysis

2020 ◽  
Vol 17 (19) ◽  
pp. 7270
Author(s):  
Daniel Enrique Rodriguez Bauza ◽  
Patricia Silveyra
Keyword(s):  
Sex Differences ◽  
Female Athletes ◽  
Meta Analysis ◽  
Sexually Dimorphic ◽  
Atopic Status ◽  
Management Plans ◽  
Disease Experience ◽  
Males And Females ◽  
Male Sex ◽  
Exercise Induced

Exercise-induced bronchoconstriction (EIB) is a common complication of athletes and individuals who exercise regularly. It is estimated that about 90% of patients with underlying asthma (a sexually dimorphic disease) experience EIB; however, sex differences in EIB have not been studied extensively. With the goal of better understanding the prevalence of EIB in males and females, and because atopy has been reported to occur at higher rates in athletes, in this study, we investigated sex differences in EIB and atopy in athletes. A systematic literature review identified 60 studies evaluating EIB and/or atopy in post-pubertal adult athletes (n = 7501). Collectively, these studies reported: (1) a 23% prevalence of EIB in athletes; (2) a higher prevalence of atopy in male vs. female athletes; (3) a higher prevalence of atopy in athletes with EIB; (4) a significantly higher rate of atopic EIB in male vs. female athletes. Our analysis indicates that the physiological changes that occur during exercise may differentially affect male and female athletes, and suggest an interaction between male sex, exercise, and atopic status in the course of EIB. Understanding these sex differences is important to provide personalized management plans to athletes with underlying asthma and/or atopy.

scholarly journals Olmiana argentina, a new genus and species of Achilidae (Hemiptera, Fulgoromorpha) from Argentina

Zootaxa ◽  
2010 ◽  
Vol 2661 (1) ◽  
pp. 47 ◽  
Author(s):  
A. GUGLIELMINO ◽  
C. BÜCKLE ◽  
A. F. EMELJANOV
Keyword(s):  
New Genus ◽  
Larval Instar ◽  
First Record ◽  
Systematic Position ◽  
New Genus And Species

The first record of the planthopper tribe Achilini from Argentina is established with the description of Olmiana argentina gen. and sp. nov.. Details of the fifth larval instar are described. The systematic position of the new genus within the Achilidae is discussed, and a key to the genera of the subtribe Achilina is provided.

scholarly journals Variation in Chin and Mandibular Symphysis Size and Shape in Males and Females: A CT-Based Study

2020 ◽  
Vol 17 (12) ◽  
pp. 4249
Author(s):  
Tatiana Sella Tunis ◽  
Israel Hershkovitz ◽  
Hila May ◽  
Alexander Dan Vardimon ◽  
Rachel Sarig ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Anatomical Landmark ◽  
Anatomical Structure ◽  
Sexually Dimorphic ◽  
Selection Theory ◽  
Size And Shape ◽  
Size Index ◽  
Sexual Selection Theory ◽  
Males And Females ◽  
Anthropological Literature

The chin is a unique anatomical landmark of modern humans. Its size and shape play an important role from the esthetic perspective. However, disagreement exists in the dental and anthropological literature regarding the sex differences in chin and symphysis morphometrics. The “sexual selection” theory is presented as a possible reason for chin formation in our species; however, many other contradictory theories also exist. This study’s aims were therefore to determine how chin and symphysis size and shape vary with sex, and to discuss “sexual selection” theory as a reason for its formation. Head and neck computed tomography (CT) scans of 419 adults were utilized to measure chin and symphysis sizes and shapes. The chin and symphysis measures were compared between the sexes using an independent-samples t-test, a Mann–Whitney test, and the F-statistic. The chin width was significantly greater in males than in females (p < 0.001), whereas the chin height, area, and size index were significantly greater in females (p < 0.001). Symphysis measures did not differ significantly between the sexes. Size accounted for 2–14% of the chin variance and between 24–33% of the symphysis variance. Overall, the chin was found to be a more heterogeneous anatomical structure than the symphysis, as well as more sexually dimorphic.

Sex determining gene transposition as an evolutionary platform for chromosome turnover

2020 ◽  
Author(s):  
Fernando Ayllon ◽  
Monica Favnebøe Solberg ◽  
François Besnier ◽  
Per Gunnar Fjelldal ◽  
Tom Johnny Hansen ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Copy Number ◽  
Sex Chromosome ◽  
Mendelian Inheritance ◽  
Variable Frequency ◽  
Sexually Dimorphic ◽  
Functional Constraints ◽  
Gene Transposition ◽  
Genotype Frequencies ◽  
Males And Females

SummaryDespite the key role that sex-determination plays in evolutionary processes, it is still poorly understood in many species. In salmonids, which are the best studied family of fishes, the master sex-determining gene sexually dimorphic on the Y-chromosome (sdY) has been identified. However, sdY displays unexplained discordance to the phenotypic sex, with a variable frequency of phenotypic females being reported as genetic males. Multiple sex determining loci in Atlantic salmon have also been reported, possibly as a result of transposition, suggesting a recent and non-random sex chromosome turnover in this species. We hypothesized the existence of an autosomic pseudocopy of sdY that is transmitted in accordance with Mendelian inheritance. To test this we developed a qPCR methodology to detect the number of sdY copies present in the genome. Based on the observed phenotype/genotype frequencies and linkage analysis among 2025 offspring from 64 pedigree-controlled families of accurately phenotyped Atlantic salmon, we identified both males and females carrying one or two autosomic copies in addition to the Y-specific copy present in males. Copy number frequencies were consistent with Mendelian inheritance. Pseudocopy loci were mapped to different chromosomes evidencing non-random transitions of the sex determining gene in Atlantic salmon and the existence of functional constraints for chromosome turnover.

scholarly journals Cuticular hydrocarbons for identifying Sarcophagidae (Diptera)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hannah E. Moore ◽  
Martin J. R. Hall ◽  
Falko P. Drijfhout ◽  
Robert B. Cody ◽  
Daniel Whitmore
Keyword(s):  
Cuticular Hydrocarbons ◽  
Gas Chromatography Mass Spectrometry ◽  
Sexually Dimorphic ◽  
Adult Males ◽  
History Museum ◽  
Chemical Profiles ◽  
Males And Females ◽  
Species Specific ◽  
Flesh Flies ◽  
Eleven Species

AbstractThe composition and quantity of insect cuticular hydrocarbons (CHCs) can be species-specific as well as sexually dimorphic within species. CHC analysis has been previously used for identification and ageing purposes for several insect orders including true flies (Diptera). Here, we analysed the CHC chemical profiles of adult males and females of eleven species of flesh flies belonging to the genus Sarcophaga Meigen (Sarcophagidae), namely Sarcophaga africa (Wiedemann), S. agnata Rondani, S. argyrostoma Robineau-Desvoidy, S. carnaria (Linnaeus), S. crassipalpis Macquart, S. melanura Meigen, S. pumila Meigen, S. teretirostris Pandellé, S. subvicina Rohdendorf, S. vagans Meigen and S. variegata (Scopoli). Cuticular hydrocarbons extracted from pinned specimens from the collections of the Natural History Museum, London using a customised extraction technique were analysed using Gas Chromatography–Mass Spectrometry. Time of preservation prior to extraction ranged between a few weeks to over one hundred years. CHC profiles (1) allowed reliable identification of a large majority of specimens, (2) differed between males and females of the same species, (3) reliably associated males and females of the same species, provided sufficient replicates (up to 10) of each sex were analysed, and (4) identified specimens preserved for up to over one hundred years prior to extraction.

Immature stages of Calycopis bellera (Hewitson) and C. janeirica (Felder) (Lepidoptera, Lycaenidae, Theclinae, Eumaeini): Taxonomic significance and new evidence for detritivory

Zootaxa ◽  
2009 ◽  
Vol 2325 (1) ◽  
pp. 39-61 ◽  
Author(s):  
MARCELO DUARTE ◽  
ROBERT K. ROBBINS
Keyword(s):  
Morphological Characters ◽  
Sexually Dimorphic ◽  
Immature Stages ◽  
Taxonomic Significance ◽  
Larval Instars ◽  
Species Groups ◽  
Males And Females ◽  
First Time ◽  
New Evidence

Details of egg, larval, and pupal morphology are described and illustrated for Calycopis bellera (Hewitson) and C. janeirica (Felder), with a special emphasis on larval chaetotaxy. Wild-caught Calycopis females laid eggs on dead leaves in the laboratory, and the caterpillars successfully completed development on an artificial agar diet to which no leaves were added. Males and females of the sexually dimorphic C. bellera had been previously placed in different genera or different species groups. Calycopis janeirica had been chronically misidentified (and misspelled C. jeneirica). Males and females of this species appear to be correctly associated for the first time. Whereas C. bellera has five larval instars—as reported previously for C. caulonia—C. janeirica has four. Morphological characters of the immatures of C. bellera and C. janeirica are summarized in a table and compared with those of other reared Calycopis species.

Description and systematic affinity of Alaninema ngata n. sp. (Alaninematidae: Panagrolaimorpha) parasitising leaf-veined slugs (Athoracophoridae: Pulmonata) in New Zealand

Nematology ◽  
2013 ◽  
Vol 15 (7) ◽  
pp. 859-870 ◽  
Author(s):  
Elena S. Ivanova ◽  
Sergei E. Spiridonov ◽  
Walter C. Clark ◽  
Maria Tourna ◽  
Michael J. Wilson ◽  
...  
Keyword(s):  
New Zealand ◽  
Cylindrical Body ◽  
Systematic Position ◽  
Nerve Ring ◽  
Anterior Intestine ◽  
Males And Females ◽  
Tail Tip ◽  
18S Rdna Sequence ◽  
Partial 18S ◽  
Male Genital

A new Alaninema species associated with leaf-veined slugs (Athoracophoridae) in New Zealand is described and illustrated. Alaninema ngata n. sp. is characterised by a very long, cylindrical body, rounded head bearing two circles of cephalic papillae and amphids, shallow stoma with three bifid teeth, muscular, cylindroid pharynx lacking valves, enlarged, rounded cardia, nerve ring crossing the anterior intestine, excretory pore situated just posterior to nerve ring, monodelphic females with post-median vulva, thick-shelled eggs covered with prominent tubercles, monorchic males with short testis reflection, reduced number of male genital papillae, strong equal spicules and gubernaculum and tail tip bearing about 20 digitate processes. It is distinguished from A. venmansi and A. njoroensis by having a larger body size (mean 8.3 mm and 13.8 mm in males and females, respectively vs 8.2 mm females in A. venmansi and 4.8 mm and 5.5 mm in A. njoroensis males and females, respectively) and more anterior vulval position (V = 51.6 vs 70 and 66.4 in A. venmansi and A. njoroensis, respectively). Analyses of a partial 18S rDNA sequence indicate that A. ngata n. sp. is affiliated to the Panagrolaimorpha. The systematic position, host range and distribution of A. ngata n. sp. are discussed.

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