Oviparous Females Research Articles

Seasonal and inter-annual dynamics of biological parameters for mysid Paracanthomysis shikhotaniensis in Peter the Great Bay (Japan Sea)

Size and sex structure of the mysid Paracanthomysis shikhotaniensis aggregations in Peter the Great Bay (Japan Sea) is considered. The samples were collected at the depth of 0.5–2.0 m at Reineke Island in May-October of 2014–2018. All sampled mysids (1601 ind.) were measured under binocular microscope with accuracy of 0.1 mm, weighted by torsion scales with accuracy of 1 mg, and separated to males, females and juveniles. The females were differentiated by 5 stages of their development: 1) immature females with oostegetic rudiments; 2) oviparous females; 3) females with embryos in the marsupia bags without stalk-eyes with black pigment; 4) females with embryos in marsupia bags with black eyes; and 5) spawned females with empty marsupii. Their body length varied from 5.0 to 27.8 mm, being much larger in spring and early summer than in late summer and autumn. Juveniles were absent in spring, but abundant in July-October. Females were larger than males, their body length varied from 9.0 to 27.8 mm, whereas the length of males — from 8.3 to 19.0 mm. Seasonal variations of the size structure were similar in different years, with small deflections due to changes of water temperature and weather conditions. In contrast, sex structure of the mysid aggregations had significant interannual differences. The females to males ratio was almost stable from June to September (females prevailed), but changed to males domination in October. Spawning of P.shikhotaniensiswas extended in time because of several generations spawned, that was confirmed by permanent occurrence of females with embryos at different stages of development.

State of aggregations and biological characteristics for mysid Neomysis awatschensis in the northern Amur Bay (Peter the Great Bay, Japan Sea)

Size and sex structure of estuarine-freshwater mysid Neomysis awatschensis in the northern Amur Bay is considered, time of their aggregations formation is determined, and their biomass is estimated on the data of surveys conducted in 2014–2019. The samples were collected at the depth of 0.5–2.0 m in the daytime in May-July. The catches were recalculated per 1 m3 of water. All collected mysids (2212 ind.) were measured under binocular microscope with accuracy of 0.1 mm, weighted by torsion scales with accuracy of 1 mg, and separated to males, females and juveniles. The females were differentiated by 5 stages of their development: 1) immature females with oostegetic rudiments; 2) oviparous females; 3) females with embryos in the marsupia bags without stalk-eyes with black pigment; 4) females with embryos in marsupia bags with black eyes; 5) spawned females with empty marsupii. Time and duration of N. awatschensis aggregating changed by years in dependence on hydrological and weather conditions; the aggregations were either monospecific or mixed with another mysid species — N. mirabilis. The maximum mysid biomass could exceed 500 g/m3 that was appropriate for commercial fishery. The maximum body length of mysid females was 13.7 mm, of males — 12.0 mm. The average length varied from 6.7 to 10.3 mm, being shorter in summer months than in May. Portion of males in the aggregations was always significant (16.3–50.7 %), portion of females varied from 8.7 to 52.5 %, portion of juveniles was the largest in June (29.9–75.0 %). The females to males ratio was 1 : 1 in May and July of 2014–2017, but males prevailed in June 2015 (1.0 : 1.9), whereas females prevailed in June 2016 (1.8 : 1.0). Spawning of the mysids was the most intensive in May-June, though females had embryos at different stages of development in all samples that indicated an extended period of reproduction.

DESCRIPTIONOFSEXUALESOFBRACHYCOLUSCUCUBALI(PASSERINI,1863)(HEMIPTERAAPHIDIDAE)

The hitherto unknown oviparous females and apterous males of Brachycolus cucubali(Passerini,1863), living in pseudogalls on Silene vulgaris(Moench) Garcke, (1869) (Caryophyllaceae), are described based on material from the North-West of Iberian Peninsula (Province of León). Sampling and morphometric data are given for every morph. Also, field data of monitored Brachycolus cucubali colonies are reported and information of polyphenismin males is discussed.

Structure of the reproductive system of the sexual generation of the endemic Arctic species Acyrthosiphon svalbardicum and its temperate counterpart Acyrthosiphon pisum (Hemiptera, Aphididae).

The Arctic aphids live briefly and must breed quickly to survive. Shortened life cycle, with only two generations: the stem mother and sexuales-oviparous females and males is an adaptation for optimal use of the short breeding period, which lasts from late July to the end of August. Using Acyrthosiphon svalbardicum, an endemic High Arctic aphid species, we describe the structure of the reproductive system of sexual morphs and compare with its temperate counterparts, in particular the model organism the pea aphid Acyrthosiphon pisum. Generally, the histological composition and ultrastructure of reproductive system of sexuales of A. svalbardicum is broadly similar to the reproductive systems described already in other species of aphids. The unique characters include in both oviparous females and males an enormous layer of the fat body, adhering to the structures of the internal reproductive system. The greatly enlarged accessory glands of males accumulate a heterogenous secretion composed of irregularly organized bunches of spicule-like structures of high electron density embedded in fine and coarse granular material. This material, unknown among temperate counterparts of A. svalbardicum, during mating is transported from the accessory glands of the male to its ejaculatory duct, where it is mixed with the ejaculate, and then is transferred to the spermatheca of the oviparous female.

BIOLOGICAL CHARACTERISTICS OF MYSID NEOMYSIS MIRABILIS IN DEPENDENCE ON ITS ENVIRONMENTS (PETER THE GREAT BAY, JAPAN SEA)

Size and sex structure of mysid Neomysis mirabilis in Peter the Great Bay is studied. The net samples (160 and 260 per year) were collected at the depth of 0.5–2.0 m in the southern external part of the secondary Amur Bay (at Popov and Reineke Islands) and in its northern internal part, over the total area of approximately 3 km2, in the daytime in May-September from 2014 to 2017. The catch was recalculated per 1 m3of water. The water temperature was measured and weather conditions were recorded. All mysids (2926 ind.) were measured under binocular microscope with accuracy of 0.1 mm, weighted by torsion scales with accuracy of 1 mg, and separated to males, females and juveniles. The females were differentiated by 5 stages of development: 1) immature females with oostegetic rudiments, 2) oviparous females, 3) females with embryos in the marsupia bags without stalk-eyed with black pigment, 4) females with embryos in marsupia bags with black eyes, 5) spawned females with empty marsupii. The females prevailed: 71.3–97.0 % in the southern Amur Bay and 39.0–56.7 % in the northern Amur Bay, while the portion of males was 2.2–28.7 % and 20.9–43.3 %, accordingly. The body length varied from 3.0 to 23.5 mm; the females and males had the same sizes, on average 14.5–15.4 mm in the southern Amur Bay and 8.3–11.2 mm in the northern Amur Bay, with slight decreasing from spring to summer. The spawning was extended in time because of several generations changing. Mysid females with eggs, their embryos at different stages of development, and juveniles of different size were presented permanently. Aggregations of N. mirabilis formed for a short time starting in middle April — middle July in the southern Amur Bay and in middle May — late July in the northern Amur Bay. The mysid biomass in the aggregations was 3–5 g/m2 and 10–500 g/m2in these areas, respectively, that is appropriate for the commercial fishery. Spatial difference of the mysid biological parameters and abundance is explained by different environmental conditions in the internal and external areas of the Amur Bay.

A further contribution to the knowledge of Uroleucon species (Hemiptera, Aphididae) living on Adesmia (Fabaceae) in southern South America, with description of a new species from Chile.

Uroleucon (Hemiptera, Aphididae, Macrosiphini) is a highly diverse and widely distributed genus. Most of its species are hosted by plants of the Asteraceae or Campanulaceae, but three species from the southern end of South America have specialized to live on plants of the genus Adesmia (Fabaceae). New morphological and chorological data are provided for U. adesmiae Mier Durante and Ortego and U. naheulhuapense Nieto Nafría von Dohlen, with a description of the alate viviparous female of the latter species. U. australe Nieto Nafría Mier Durante, sp. n. is described from apterous viviparous females, oviparous females and males from four localities in the Chilean regions of Aysén and Magallanes; it is very close to U. nahuelhuapense, both morphologically and genetically. Contrary to what is typical for aphids, the males of U. australe have a greater number of distinguishing characters than are found in viviparous females. A modification of the identification key to the apterous viviparous females of the known Uroleucon species in South America by Nieto Nafría et al. (2019) is presented.

Neural circuitry linking mating and egg laying in Drosophila females.

Mating and egg laying are tightly cooordinated events in the reproductive life ofall oviparous females. Oviposition is typically rare in virgin females but is initiated after copulation. Here we identify the neural circuitry that links egg laying to mating status in Drosophila melanogaster. Activation of female-specific oviposition descending neurons (oviDNs) is necessary and sufficient for egg laying, and is equally potent in virgin and mated females. After mating, sex peptide-a protein from the male seminal fluid-triggers many behavioural and physiological changes in the female, including the onset of egg laying1. Sex peptide is detected by sensory neurons in the uterus2-4, and silences these neurons and their postsynaptic ascending neurons in the abdominal ganglion5. We show that theseabdominal ganglion neurons directly activate the female-specific pC1 neurons. GABAergic (γ-aminobutyric-acid-releasing) oviposition inhibitory neurons (oviINs) mediate feed-forward inhibition from pC1 neurons to both oviDNs and their major excitatory input, the oviposition excitatory neurons (oviENs). By attenuating the abdominal ganglion inputs to pC1 neurons and oviINs, sex peptide disinhibits oviDNs to enable egg laying after mating. This circuitry thus coordinates the two key events in female reproduction: mating and egg laying.

Micromorphology of the model species pea aphid Acyrthosiphon pisum (Hemiptera, Aphididae) with special emphasis on the sensilla structure

The pea aphid complex [Acyrthosiphon pisum (Harris 1776)] (Hemiptera, Aphididae), listed among the 14 aphid species of the greatest economic importance, is a globally distributed key pest of pulse crops. Since the pea aphid is a well-studied model organism, an enormous amount of literature has been published about this species. However, comprehensive morphological analyses using scanning electron microscopy (SEM), focused on all body parts of adult viviparous and sexual generations of A. pisum, are lacking. Thus, we present the first detailed morphological description of all body parts of adult wingless and winged viviparous females (parthenogenetic generation) as well as oviparous females, winged and wingless males (sexual generation), representing the most common A. pisum pea biotype. In particular, the sensilla of the body surface, antennae, mouthparts, legs and male genitalia are mapped by the high-resolution scanning electron microscope. The morphological diversity of sensilla is discussed in the context of their function and the biology of aphids.

Conifer-feeding aphids (Insecta: Hemiptera: Aphididae) of India, Bhutan and Nepal with descriptions of three new species of the genus Cinara

Here, we present a review of the conifer-feeding aphids of India, Bhutan and Nepal, which includes 30 species. Three new species, viz., Cinara (Cinara) bhutanica sp. nov., associated with Pinus wallichiana in Eastern Himalaya (Bhutan), Cinara (Cupressobium) asishghoshi sp. nov., which infest Juniperus squamata and Cinara (Cupressobium) himalayaensis sp. nov., which are associated with Taxus baccata in Northwest Himalaya (India) respectively, are described and illustrated. A hitherto unknown oviparous female of Cinara lachnirostris Hille Ris Lambers is also described and illustrated. Cinara (Cinara) takahashii nom. nov. is proposed here as a replacement name for Cinara (Cinara) orientalis (Takahashi, 1925), which is a junior secondary homonym of Cinara (Schizolachnus) orientalis (Takahashi, 1924). Cinara indica Verma syn. nov. is proposed as new junior synonym of Cinara confinis (Koch). Cinara maculipes and Cinara takahashii nom nov. from Bhutan and C. tenuipes from Nepal are reported for the first time. Taxonomical and biological information about the presented species are given along with their distribution. A key to identifying the conifer-feeding aphids of India, Bhutan and Nepal is also provided. urn:lsid:zoobank.org:pub:F4A3C8D8-3E11-450E-9EC5-90C7F8409B46

A review of the aphid genus Macrosiphoniella del Guercio, 1911 (Hemiptera: Aphididae) in the USA with description of a new species

Here we present a review of the 18 species of the Macrosiphini genus Macrosiphoniella (Hemiptera: Aphididae) known to occur in the United States of America, representing two subgenera, Macrosiphoniella and Phalangomyzus Börner, 1939. We report key features for all species including colour in life and pigmentation on slides of apterous and alate viviparous females of all 18 species. Distributional data, host plants, and biological notes of the reviewed species are presented. Apterous, alate and oviparous females of a new native USA species, Macrosiphoniella sunshine sp. nov., associated with Eriophyllum lanatum (Asteraceae) are described from specimens collected in California, Oregon, and Washington. Keys to apterous and alate viviparous females of the Macrosiphoniella in the USA are also provided. http://zoobank.org/urn:lsid:zoobank.org:pub:A15D7190-8E74-4AC6-84B2-6B8AE9A4454C http://zoobank.org/urn:lsid:zoobank.org:act:3C3FA8B4-9EA5-4F09-ABF0-31EDC3826E13

A new species of Obtusicauda (Hemiptera: Aphididae) from Iran living on Artemisia

A new species of the genus Obtusicauda Soliman, 1927 (Hemiptera: Aphididae: Aphidinae: Macrosiphini) is described and illustrated from North-Khorasan province, Iran: Obtusicauda iranica sp. n. The species is described based on apterous viviparous females, an alate viviparous female and oviparous females found living on the terminal parts of shoots of Artemisia sieberi, A. kopetdaghensis, A. scoparia and Artemisia sp. (Asteraceae). The new species is morphologically most similar to Obtusicauda dolychosiphon (Umarov, 1964). This holocyclic aphid is not typically attended by ants.http://www.zoobank.org/urn:lsid:zoobank.org:pub:AE524BA1-B04C-40EF-A818-724F6AA48669

The reproductive system of the male and oviparous female of a model organism-the pea aphid, Acyrthosiphon pisum (Hemiptera, Aphididae).

The structure of the reproductive system of the sexual generation—males and oviparous females—of the pea aphid Acyrthosiphon pisum (Harris) (Hemiptera, Aphididae), a serious pest of cultivated plants of Fabaceae, was investigated. For the first time we describe the morphology, histology and ultrastructure of the reproductive system in both morphs of the sexual generation of aphids within one species, using light and fluorescent microscopy, as well as transmission and scanning electron microscopy. The results revealed that males have testes composed of three follicles fused by the upper ends of the vasa efferentia, the vasa deferentia run independently, the accessory glands are asymmetric and the ejaculatory duct shortened. Oviparous females have ovaries composed of seven ovarioles each. The lateral oviducts join to a short common oviduct connected with the unpaired spermatheca and paired accessory glands. Yolky eggs with an aggregation of symbiotic bacteria at the posterior pole are produced. Histologically, the components of genital tracts are broadly similar: the epithelial cells of the walls of the vasa deferentia and accessory glands of the male and oviparous female have secretory functions which correlate with the age of the studied morphs. We also found symbiotic bacteria within the vasa deferentia epithelial cells in males and within the cells of the lateral oviducts of females. Because the pea aphid is listed among the 14 species that are of the greatest economic importance, our results will be useful for managing aphid populations, protecting plants and ensuring global food security.

Description of oviparous female of <i>Cinara nigritergi</i> Mamontova, 2002 (Hemiptera: Aphididae)

A previously unknown oviparous female of Cinara nigritergi Mamontova, 2002 is described and illustrated. Cinara nigritergi is for the first time reported from Russia (Karelia) where it was found feeding on Pinus sylvestris.

Aphis (Hemiptera, Aphididae) species living on Baccharis (Asteraceae) insouthern South America, with description of three new species.

Aphid specimens belonging to the genus Aphis (Hemiptera, Aphididae, Aphidinae) collected on species of Baccharis (Asteraceae) in localities of Argentina and Chile, preserved in the Natural History Museum in London and in the Universidad de León collections, have been studied. They belong to six species: Aphis craccivora, Aphis gossypii and Aphis spiraecola, which are widely-distributed and polyphagous, and the new species: Aphis ingeborgae Nieto Nafría and Brown sp. n., Aphis conspicua Nieto Nafría and Mier Durante sp. n. and Aphis fuentesi Nieto Nafría and Ortego sp. n. which are here described from apterous and alate viviparous females, and also from oviparous females and males in the case of Aphis fuentesi. These six species plus the native and monophagous A. coridifoliae are those known in southern South America living on plants of Baccharis. Diagnostic features of new species and an identification key for apterous viviparous females of these seven species are presented.

A new species of Aphis Linnaeus (Hemiptera: Aphididae) on Picris echioides in Britain.

Aphis cornuta sp. n. living on the basal parts of Bristly Oxtongue, Helminthotheca echioides (L.) Holub (=Picris echioides L.), is described, based on apterous and alate viviparous females, oviparous females and apterous males collected in southern England.

Additions to the aphid fauna of Wrangel Island due to climate change withbr />redescription of the oviparous female of Pterocomma groenlandicum Hille Ris Lambers, 1952 (Hemiptera, Aphidoidea).

The article contains new data on the Aphidoidea of Wrangel Island collected in 2015. Previously, at least four species were known. Two of them, Aphis polaris Stekolshchikov et Khruleva, 2014 and Metopolophium sabihae Prior, 1976, were regularly observed on the island in the 1980s and 1990s. Pterocomma groenlandicum Hille Ris Lambers, 1952 and Myzus (Nectarosiphon) polaris Hille Ris Lambers, 1952, were first collected in 2006. In 2015 three more species were found: Brachycaudus (Mordvilkomemor) rumexicolens (Patch, 1917), Cavariella aegopodii (Scopoli, 1763), and Pemphigus saliciradicis (Börner, 1950). This last species represents a first record for the territory of Russia whereas C. aegopodii had not previously been collected in tundra landscapes. In 2015, a total of seven aphid species were collected. For one of the four previously noted species, M. sabihae, a sharp increase in its abundance is recorded. We propose that the increase in aphid species diversity is due to climate warming in the Russian High Arctic. A detailed redescription of the oviparous female of P. groenlandicum is also provided.

Differential reproductive investment in co-occurring oviparous and viviparous common lizards (Zootoca vivipara) and implications for life-history trade-offs with viviparity

Live-bearing reproduction (viviparity) has evolved from egg-laying (oviparity) independently many times and most abundantly in squamate reptiles. Studying life-history trade-offs between the two reproductive modes is an inherently difficult task, as most transitions to viviparity are evolutionarily old and/or are confounded by environmental effects. The common lizard (Zootoca vivipara) is one of very few known reproductively bimodal species, in which some populations are oviparous and others viviparous. Oviparous and viviparous populations can occur in sympatry in the same environment, making this a unique system for investigating alternative life-history trade-offs between oviparous and viviparous reproduction. We find that viviparous females exhibit larger body size, smaller clutch sizes, a larger reproductive investment, and a higher hatching success rate than oviparous females. We find that offspring size and weight from viviparous females was lower compared to offspring from oviparous females, which may reflect space constraints during pregnancy. We suggest that viviparity in common lizards is associated with increased reproductive burden for viviparous females and speculate that this promoted the evolution of larger body size to create more physical space for developing embryos. In the context of life-history trade-offs in the evolution of viviparity, we suggest that the extent of correlation between reproductive traits, or differences between reproductive modes, may also depend on the time since the transition occurred.

The aphid fauna (Hemiptera, Sternorrhyncha, Aphidomorpha) of Murmansk province (Russia), with description of Aphis khrulevi sp. nov. and Dysaphis karyakini sp. nov. and males of Chaitophorus nigricantis Pintera, 1987

An updated aphid (Hemiptera, Aphidomorpha) check-list of Murmansk province (European Russia) is presented, it includes 162 species. Chaitophorus nigricantis Pintera, 1987, Schizaphis nigerrima (Hille Ris Lambers), Hyperomyzus (Neonasonovia) zirnitsi Hille Ris Lambers, Nasonovia (Kakimia) vannesii Stenseth, Plocamaphis flocculosa goernitzi Börner and Schizaphis graminum gigjai Stroyan are recorded for the first time from Russia. Both apterous and alate males of Chaitophorus nigricantis nigricantis Pintera are described. Two new aphid species are described: Aphis khrulevi sp. nov. from fundatrices and apterous viviparous females, living on Veronica longifolia and Dysaphis karyakini sp. nov. from apterous and alate viviparous females, oviparous females and males, living on Cenolophium denudatum. Comments about the distribution and biology of aphids in this Northern part of Europe, and on the completeness of the list are given.

A non-invasive manual method for the assessment of pregnancy in female Scyliorhinus canicula catsharks

Enhanced survival of oviparous shark populations can rely on only one easily applicable method. We tested a powerful method to retrieve egg cases from dead oviparous females at the fish market which is non-invasive. We approved this method for Scyliorhinus canicula and Scyliorhinus stellaris (smallspotted catshark and Nursehound) in Valletta, Malta in 2014. Here, catsharks are landed in whole, whereas in many other Mediterranean countries sharks are already eviscerated when brought ashore. Saving egg cases bears the grateful opportunity to rescue shark embryos and this then helps again to restore fish stocks. The common work flow of fishermen is to throw away the egg cases when eviscerating the shark and so the embryos were left in the bin to die. To apply a non-invasive method is very important at fish markets where sharks are landed in one piece as fish brokers do not tolerate many dissections. So, our goal was to detect pregnant females with maximum accuracy and dissect only females with egg cases inside. Formerly, the common method used by members of Sharklab-Malta was to dissect females more or less randomly based on only two parameters (i) a total length above 40cm and (ii) a relatively corpulent body shape. This was not effective as many females were dissected without containing egg cases. This led to the more problematic fact that pregnant individuals were not found and so their offspring died in the end. The basic concept in our newly tested method is based on using a fixed touching pattern which allows to screen the belly of all females available simply by hand. To screen one female only 2 seconds are needed, and this works surprisingly well. We called this method “gotIt” simply because we got all available egg cases and could save all embryos. A validation underpinned the success and showed that gotIt works with 100% accuracy. After rescuing the egg cases they were transported to an aquarium. Egg cases were attached to a lanyard by their tendrils and left for development in the tank for 3-6 months (depending on their initial developmental stage at the fish market) at a water temperature of 15-19°C. After hatching, sharks were fed with squid and released into the sea. The number of rescued embryos arose significantly from five to above hundreds of shark pups which were saved and released by applying gotIt. Additionally, fishermen can be encouraged to use this method, as awareness programs can be promoted to encourage consumption of this sustainable fish, which can therefore increase the marketable prices. Widely applied, gotIt can help to preserve oviparous shark populations at fish markets where sharks are landed whole.

Pheromone gland development and monoterpenoid synthesis specific to oviparous females in the pea aphid

BackgroundAphids display “cyclic parthenogenesis,” in which parthenogenetically and sexually reproducing morphs seasonally alternate in the aphid annual life cycles. There are various characteristics that differ between asexual viviparous and sexual oviparous females. In oviparous females, swollen cuticular structures (~ 10 μm in diameter), called “scent plaques,” are scattered on the surface of hind tibias, and secrete monoterpenoid sex pheromones. However, the developmental processes of the pheromone glands and the biosynthetic pathways of monoterpenoid pheromones have yet to be elucidated.ResultsComparisons of the developmental processes that form hind tibias between sexual and parthenogenetic females revealed that, in sexual females, the epithelial tissues in proximal parts of hind tibias become columnar in fourth instar nymphs, and circular pheromone glands with Class 1 gland cells appear in adults, although they do not appear in parthenogenetic females. Furthermore, by comparing the expression levels of genes involved in the mevalonate pathway, which is required for monoterpenoid synthesis, we show that genes that encode the downstream enzymes in the pathway are highly expressed in hind tibias of sexual females.ConclusionGlandular tissues of scent plaque are differentiated from the fourth instar in sexual females, while parthenogenetic females lack the glandular cells. Only the downstream steps of the mevalonate pathway appear to occur in scent plaques on hind tibias of sexual females, although the upstream steps may occur somewhere in other body parts.