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The ontogeny of the cytheroidean species Loxoconcha japonica is documented from the earliest instar to the adult. The first instar (instar A-8) of L. japonica is different from that of cypridoidean species in that it has an additional appendage, the furca, present. From instar A-7 onwards, the appearance of the appendages is similar to that of cypridoidean and bairdioidean species. The furca is well developed in instars A-8 to A-5, and is probably an important appendage in these early instars, despite its reduced form in the adults. Some appendages of L. japonica (e.g. the antennae) gain very few setae and claws through ontogeny, compared with species from other superfamilies. This possibly reflects paedomorphic evolution of this species.  相似文献   

3.
Postembryonic females and males Diaphanosoma brachyurum from Lake Glubokoe (Moscow) have 3–4 and 3 juvenile instars, respectively. Females and males of the first three postembryonic instars can be identified by the different number of setae and setal rudiments on the proximal and distal segments of the exopodite of the swimming antennae: 3 + 7; (i + 3) + 7; 4 + (i + 7), respectively (i = rudiment of seta). The subsequent instars have 4 + 8 long plumose setae on these segments, but the fourth instar has the proximal lateral seta of the distal exopod segment slightly shorter and thinner than the others. The antennules and copulatory appendages of males are instar-specific. Diaphanosomas show small increments in body length during the postembryonic molts. The largest increments (about 115 m) occur during the first or second molts. The allometric equation of Huxley (1924) was used for a comparison of the relative growth rate of different body parts. In the middle of summer, the head and swimming antennae with the body and the antennal exopodite with the antennal basipodite grow in isometry. At the same time, the branches of the swimming antennae and their setae show allometric growth: the exopodite and distal setae grow faster than the endopodite and the lateral setae, respectively.  相似文献   

4.
The post-embryonic development of the appendages of the Cyprididae ostracod Heterocypris salina (Brady, 1868) are described in detail and compared with those of other podocope species documented in previous studies. Generally, the appearence of limbs during onotgeny of H. salina is similar to that of other species, but small differences in limb morphologies were identified between H. salina and other Cyprididae species, including other Heterocypris species. Some features appear either earlier or later in the development of H. salina compared with other species, even species of the same genus. These features may be useful characters for phylogenetic analyses at the genus and family levels.  相似文献   

5.
The ostracod genus Neonesidea is broadly distributed in shallow marine waters. The ontogeny of the N. schulzi (Bairdiidae) is described in detail by studying the development of the appendages and variations in carapace form, size and structure. Neonesidea schulzi has eight post-embryonic instars, and a gap in its ontogenetic development during instar A-6, where no new Anlage is added. The Anlagen of the copulatory organs and the forked terminal claw of second antenna appear in the seventh (A-1) instar, and the first thoracic legs of podocopid ostracods are shown to descend from the thoracic region. For the first time in ostracods, observations of moulting from sixth and seventh instars are presented.  相似文献   

6.
Control of Anopheles albimanus, the main vector of malaria on the coast of the State of Chiapas, is based mainly on application of chemical insecticides, which has resulted in resistance to most registered insecticides. Strategies for biological control may provide sustainable alternatives. We report on the lethal effects of a native isolate of Gliocladium virens on An. albimanus larvae and adults, compared to that of strains of Beauveria bassiana and Metarhizium anisopliae. Conidial suspensions of G. virens, B. bassiana and M. anisopliae cultured on Sabouraud agar were tested in bioassays with An. albimanus larvae and adults. Mosquito larvae were more susceptible to all fungi, compared to adults. On early and late instar larvae, M. anisopliae showed the most pathogenic effect (LC50 of 1.4×105 conidia/mL in early instars; 1.1×105 conidia/mL in late instars), followed by G. virens (LC50 of 3.3×105 conidia/mL in early instars and 3.5×106 conidia/mL in late instars). Metarhizium anisopliae sensu lato and the native G. virens could be considered good choices for An. albimanus control in southern Mexico.  相似文献   

7.
The three larval instars of Hydaticus (Guignotites) tuyuensis Trémouilles are described and illustrated for the first time, emphasizing the morphometry and chaetotaxy. Second- and third-instar larvae of the known species of the subgenus Guignotites Brinck are characterized by a trilobate median process of prementum. All larval instars of H. tuyuensis, however, have a bilobate process, similar to that present in the known species of the subgenus Hydaticus Leach. This implies that a trilobate process cannot be used as a diagnostic character for Guignotites. Alternatively, Guignotites as presently defined may not represent a natural group. A cladistic analysis of 57 larval characters suggests that the genus Hydaticus shares a common origin with the clade composed of the genera Eretes Laporte and Thermonectus Dejean, based on the following synapomorphies: (i) abdominal segment VII almost completely sclerotized ventrally; the absence of (ii) additional ventroapical pores on the third antennomere, (iii) setae FE4 and FE6, (iv) additional setae on the femur and (v) additional setae on the tibia; and the presence of (vi) setae on the median process of prementum and (vii) spinulae on the second labial palpomere. A bilobate or trilobate median process of the prementum and the submedial insertion of seta AN3 distinguish Hydaticus from the remaining genera of Dytiscinae studied.  相似文献   

8.
The egg and the five instars of Ectemnostega are described based on examined material and published information. The characters most useful in identifying nymphs of Ectemnostega are body and head lengths and widths; number of transverse sulcations of the rostrum; chaetotaxy of mesofemur, meso- and metatibiae, metatarsus, and pterothorax; and grade of development of wing pads. A key to the five nymphal instars of Ectemnostega is provided. The egg of E. quadrata is figured and described for the first time; and the five instars are redescribed in detail and illustrated, with emphasis on the morphometry and chaetotaxy of selected structures.

Se describe el huevo y los cinco estadios de Ectemnostega a partir de material examinado e información publicada. Los caracteres mas útiles para identificar las ninfas de Ectemnostega son: longitudes y anchos de cuerpo y cabeza; número de: crestas transversales del rostro, quetotaxia del mesofemur, meso- y metatibias, metatarso, y pterotórax; y grado de desarrollo de pterotecas. Se provee una clave para identificar los cinco estadios de Ectemnostega. Por primera vez se ilustra y describe el huevo de E. quadrata; y se redescriben en detalle e ilustran los cinco estadios, con énfasis en la morfometría y quetotaxia de ciertas estructuras.  相似文献   

9.
Summary The lung mite P. africanus Fain, 1959 and its larva from a new host (Mandrillus leucophaeus) is described and compared to the most frequently found species, P. simicola Banks, 1901. The chaetotaxy of the legs is essentially identical, but leg IV of P. simicola bears 5 spines and 10 setae, while in P. africanus one of the spines is replaced by a seta. Also, very fragile small setae were discovered at the base of the ambulacra on legs II, III and IV in P. africanus and only on leg IV in P. simicola. The chaetae of the ‘Haller's organ’ on leg I are described in detail, and formulae for the chaetotaxy of all legs and measurements of both species are given. ac]19860213  相似文献   

10.
斜脉蝠蛾幼虫分类特征研究   总被引:4,自引:0,他引:4  
余虹  高祖Xun 《昆虫学报》1993,36(4):465-468
本文研究报道了冬虫夏草主要寄主之一斜脉蝠蛾Hipialus oblifurcus Chu et Wang幼虫头、胸、腹各部分的形态特征、颜色、毛序及各龄幼虫的头宽和体长,可作为鉴别种类的依据。  相似文献   

11.
Sinev  Artem Y. 《Hydrobiologia》2000,437(1-3):197-202
As in most other Chydoridae, Alona affinis has two juvenile instars in both sexes and development of the male is similar to that of previously studied species. Several interesting traits were found in the development of the first trunk limb. Males with abnormal morphology in sex-linked characters and ephippial females with a postabdomen similar to that of the adult male are described.  相似文献   

12.
The Entocytheridae is a cytheroidean family that is known for its commensal mode of life on other crustaceans. However, due to their small size and large sexual dimorphism in the sizes of the carapace, the ontogeny of the entocytherids is poorly understood. This paper documents the basic body plans and pore systems of the entocytherid Uncinocythere occidentalis (Kozloff & Whitman, 1954) Hart, 1962 through ontogeny and compares them with other podocope groups. U. occidentalis has seven juvenile stages, one less than other cytheroidean groups. The general appearance of the limbs during the ontogeny of U. occidentalis is similar to that of other podocope ostracods, such as Limnocythere inopinata (Cytheroidea) Loxoconcha japonica (Cytheroidea),Eucypris virens (Cypridoidea), and Neonesidea oligodentata (Bairdioidea) with the exception of the maxillula. The adult maxillula of U. occidentalis is reduced to just a palp and third masticatory lobe (endite), and the third masticatory lobe and branchial plate of this appendage form later in the ontogeny compared with other podocope species (i.e., these features show post displacemental ontogenetic development). The number of the pore systems of the earliest juvenile (A-7) of U. occidentalis is 10, and is different from that of the corresponding stage of other cytheroidean groups which have 9. This fact, together with the different mode of development of the maxillula, indicates that the entocytherids are not only highly specialized to their commensal mode of life but that they are also phylogenetically distant from most other cytheroidean families, possibly differentiating from the others during the early evolution of the cytherids.  相似文献   

13.
Abstract Xenochironomus tuberosus sp. nov. from southern China is here described and illustrated as male imagines. The new species is separated from other known species of this genus in having frontal tubercle, unusual stout setae on tergite VI, characteristic chaetotaxy on tergite IX and unique superior volsela. Based on the new species, an emendation to the diagnosis of the genus is given. This paper is the first record of genus Xenochironomus from China.  相似文献   

14.
The genus Paegniodes Eaton, 1881 and its type species P. cupulatus (Eaton, 1871) have never been described in detail completely. In this article, all stages are described and photographed. Compared to other heptageniid genera, the adults of P. cupulatus have a more colourful body, smaller hindwings but larger titillators. The nymphs of this species have no setae or tubercles on the body and no emarginations on the head capsule. They have smaller lamellae of the first gills, a wider labrum with a median notch, mandibles without setae on outer margins, maxillae with a row of setae and scattered setae on the ventral surface, cerci with mesal setae, and a median filament with setae on both sides. Both imaginal and nymphal stages of the genus have unique characters, so the taxon Paegniodes is recognized at the rank of genus here. It appears closely related to Rhithrogena Eaton, 1881.  相似文献   

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The Ontogeny of Neonesidea oligodentata (Bairdioidea, Ostracoda, Crustacea)   总被引:4,自引:3,他引:1  
This is the first detailed ontogenetic study of the appendages and carapace of a bairdioidean ostracod. This paper uses the development of the appendages and changes in the pore systems of the carapace through ontogeny to help determine the relationship between the Bairdioidea and other podocope groups. Neonesidea oligodentata has eight post-embryonic stages: one fewer than the Cypridoidea, Cytheroidea and Darwinuloidea. The first instar of N. oligodentata resembles that of the second instar of the Cypridoidea and Cytheroidea in terms of appendages, and it is postulated that there is an additional instar stage of N. oligodentata that molts within the egg. The general sequence of appearance of the limbs from instar A-7 onwards is similar to that of the Cypridoidea and Cytheroidea, but different from that of the Darwinuloidea. Like the Cypridoidea and Cytheroidea, N. oligodentata has a gap in its ontogenetic development during instar A-6, where no new Anlage is added. Pore system analysis of A-7 instars suggests that the Bairdioidea may be more closely related to the Cypridoidea than to the Cytheroidea.  相似文献   

18.
记述福建省刺齿属1新种:拟中华刺齿Homidia pseudosinensis sp.nov.。该新种的鉴定特征有胸部第2节后侧具近似M型的横条带,下唇毛序及腹部第4节毛序。本文提供了该物种的特征图及福建省刺齿属分种检索表。  相似文献   

19.
Phytoseiidae classification is based on idiosoma chaetotaxy and the assumed evolutionary process is seta suppression. This article aims to determine how depilation could have taken place depending on seta position, subfamily and region. For this, the occurrence of 21 variable setae on dorsal and ventral shields was determined for 1996 species in seven biogeographical regions. The occurrence of eight rare setae assumed to be past relics and 11 rarely absent setae (assumed to be undergoing a loss process) was analysed. The subfamily Phytoseiinae has ‘lost’ the highest number of primitive setae, the subfamily Amblyseiinae has ‘retained’ the highest number and Typhlodrominae has an intermediate position, except for the seta z6. The subfamily Phytoseiinae shows the highest number of setae undergoing a loss process, whereas the subfamily Typhlodrominae has lost these setae in 674 species and subfamily Amblyseiinae in 415 species, making this latter subfamily that with the most retained dorsal setae. According to spatial seta occurrence, it could be hypothesized that Amblyseiinae originated from South Gondwana, Typhlodrominae from the Euro‐America region (Laurasia zone) and Phytoseiinae from the Ethiopian area. The presently admitted classification of Phytoseiidae is discussed with regard to the occurrence of rarely present setae (assumed to have been lost in high frequency). © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112 , 606–624.  相似文献   

20.
As part of a larger project examining and comparing the ontogeny of all major taxa of the Branchiopoda in a phylogenetic context, the larval development of Caenestheriella gifuensis (Ishikawa, 1895), a Japanese spinicaudatan ‘conchostracan’, is described by scanning electron microscopy. Seven different larval stages are recognised, in most cases based on significant morphological differences. They range in length from about 200 to 850 μm. Nauplius 1 has a plumb and lecithotrophic appearance with a rounded hind body and a labrum with an incipient medial spine. Limb segmentation is mostly unclear but the second antennae have more putative segments delineated than are expressed in the later stages. Feeding structures such as the mandibular coxal process and antennal coxal spine are only weakly developed. Nauplius 2 is very different from nauplius 1 and has three large spines on the labral margin and two long caudal spines. Feeding structures such as the mandibular coxal process and various spines and setae are developed, but whether feeding begins at this stage was not determined. The mandible has developed an ‘extra’ seta on endopod segment 1, absent in Nauplius 1. The segmentation of the second antenna has changed significantly due to fusions of various early segments. Nauplius 3 is like nauplius 2 in morphological detail, but larger and more elongate. Nauplius 4 has developed a pair of small anlagen of the carapace and rudiments of the first five pairs of trunk limbs, and the coxal spine of the antenna has become distally bifid. Nauplius 5 has a larger carapace anlage, externally visible enditic portions of the elongate trunk limbs, and a pair of primordial dorsal telson setae. Nauplius 6 has a larger and partly free carapace and better-developed, partly free trunk limbs with incipient enditic, endopodal, and exopodal setation. A pair of caudal spines, dorsal to the large caudal spines, has appeared. Nauplius 7 is quite similar to nauplius 6 but is larger and has slightly longer caudal and labral spines; also, the setation of the most anterior trunks limbs is better developed. The larval development is largely similar to that of other spinicaudatans. The larval mandible, which is evolutionarily conservative within the Branchiopoda, reveals a setation pattern similar to that of the Anostraca and Notostraca (two setae on mandibular endopod segment 1). Most other spinicaudatans and all examined laevicaudatans share another setal pattern (one seta on mandibular endopod segment 1), which could indicate a close relationship among these taxa. The second antenna undergoes a special development, which provides an insight into the evolution of this limb within the Branchiopoda. In nauplius 1 the basipod, endopod, and exopod are all superficially divided into a relatively high number of segments. In later nauplii some of these have fused, forming fewer but larger segments. We suggest that this ontogeny reflects the evolution of antennae in the conchostracans. Various aspects of the morphology of the antennae are discussed as possible synapormorphies for either the Diplostraca or subgroups of the Conchostraca.  相似文献   

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