Morphological Ontogeny Research Articles

Morphological ontogeny of Oribatula pannonica (Acari, Oribatida, Oribatulidae), and comments on some species of Oribatula Berlese.

The morphological ontogeny of Oribatula pannonica Willmann, 1949 is described and illustrated. Most prodorsal setae of juveniles are of medium size, and bothridial seta is clavate. The larva has 11 pairs of gastronotal setae, including h2, most are of medium size and barbed, nymphs have 13 pairs (p3 absent), of which most are short and smooth. Basal excentrosclerites are present at nine pairs of gastronotal setae (c1, c2, d-, l-series, h1) in the larva, and at 12 pairs (c1, c2, d-, l-, h-series, p1) in the nymphs. The morphology of adult O. pannonica is compared with congeners with 13 pairs or an unknown number of notogastral setae.

Morphological Ontogeny, Ecology, and Biogeography of Fuscozetes fuscipes (Acari, Oribatida, Ceratozetidae).

The systematic status of Fuscozetes Sellnick, 1928, is not clear in the literature. Therefore, the morphological ontogeny of F. fuscipes (C.L. Koch, 1844), the type species of this genus, was investigated and compared with its congeners in this study, and a new diagnosis of Fuscozetes is given. The juveniles of F. fuscipes are light brown, with a brown prodorsum, sclerites, epimeres, and legs. In all juveniles, a humeral organ and a humeral macrosclerite are present. The gastronotum of the larva has 12 pairs of setae (h3 is present), whereas the nymphs have 15 pairs. In the larva, the gastronotal shield is weakly developed, and most gastronotal setae are short except for a slightly longer h2. Most of the gastronotal setae are inserted on the microsclerites except for h3, and several other macrosclerites and many microsclerites are present on the hysterosoma. In the nymphs, the gastronotal shield is well developed, with 10 pairs of setae (d-, l-, and h-series, and p1), and setae p2 and p3 are located on a large posteroventral macrosclerite. In all the instars, femora I and II are oval in cross-section, without a large ventral carina. Mitochondrial COI sequence data revealed a deep split between the Nearctic and Palearctic populations of F. fuscipes, and a less, but significant, divergence within each continent. These strong geographical barriers were contrasted with multiple cases of shared haplotypes over long distances in the Palearctic, indicating high migration rates in modern times.

Spawning, larval morphological ontogeny and first feeding of yellow-striped cardinalfish Ostorhinchus cyanosoma (Bleeker, 1853)

The yellow-striped cardinalfish (Ostorhinchus cyanosoma) can be found in the Indo-West Pacific region. It possesses great potential for the ornamental aquarium market due to its vibrant body coloration and tendency of group swimming. This study aims to investigate the spawning frequency and larval morphological ontogeny, and develop first feeding techniques of O. cyanosoma reared in capacity. From April 2021 to August 2022, a total of 70 spawning events were documented for the broodstock. These spawning events did not exhibit specific patterns related to seasonal or lunar cycles. The effects of four live prey treatments (mono-feeding and co-feeding of SS-type rotifer Brachionus sp. and nauplii of copepod Bestiolina coreana) on the mouth opening rate, prey ingestion rate, and prey selectivity of the 0 day-post-hatch (dph) larvae were investigated. The O. cyanosoma larvae displayed significantly higher mouth opening rate, ingestion rate and prey selectivity on the copepod nauplii over the rotifer. In the 7-d larviculture experiment, the larvae showed significant higher survival rate in the copepod feeding treatment (68%) than the rotifer feeding treatment (0%). For ontogeny, O. cyanosoma larvae appeared to be altricial (at pre-flexion stage with no gas bladder and poor-developed fins) and small-mouthed (235.94 μm) when leaving the mouthbrood. The standard length increased from 2.64 to 6.51 mm during 0 to 21dph. Ntochord flexion initiated at 12 dph, and the metamorphosis was completed by 21 dph. This study is the first attempt to document the broodstock management, first feeding protocol and larval ontogeny of O. cyanosoma. The findings could have implications for larviculture of cardinalfishes.

Morphological ontogeny of Melanozetes interruptus Zacher</p > (Acari, Oribatida, Ceratozetidae), and comments on Melanozetes Hull

The morphological ontogeny of Melanozetes interruptus Willmann, 1953 is redescribed and illustrated. The juveniles of this species are brown with dark-brown sclerites. In juveniles humeral organ and humeral macrosclerite are present, seta c1 is inserted on humeral macrosclerite, and setae c2 and c3 are inserted on microsclerites. In the larva, the gastronotal shield has seven pairs of setae (d-, l-series and h1), in the nymphs it has nine pairs (d-, l-, h-series), whereas all setae of p-series are inserted on microsclerites, which is unique in Melanozetes Hull, 1916. In most nymphs of this genus seta p1 is inserted on gastronotal shield. In the juveniles and adult the legs are stocky, all femora are flattened, and femora I and II have a large ventral carina. Solenidion ω2 on tarsus I is located anterior to solenidion ω1 and is longer than ω1. In this species tarsal setae a are clearly longer than seta s.

Morphological Ontogeny and Ecology of a Common Peatland Mite, Nanhermannia coronata (Acari, Oribatida, Nanhermanniidae).

Nanhermannia coronata Berlese, 1913, is a common and abundant oribatid species in peatlands but can be easily mistaken for N. sellnicki Forsslund, 1958, as an adult. Therefore, the identity of adults of N. coronata from several sites in Norway and Ireland was supported by the COI sequence data, and based on this material, the morphological ontogeny of this species is described and illustrated to highlight the differences between N. coronata and N. sellnicki. In all juvenile stages of N. coronata, the bothridial seta is absent, but two pairs of exobothridial setae are present, including short exp and exa reduced to its alveolus. In the larva, seta f1 is setiform, but in the nymphs, it is reduced to its alveolus. Most prodorsal and gastronotal setae of larva are short, and of nymphs they are long. In all instars, the leg segments are oval in cross section and relatively thick, and many setae on tarsi are relatively short, thick and conical, except for longer apical setae. Seta d accompanies solenidion σ on all genua, φ1 on tibia I and φ on other tibiae. We found some morphological characters that clearly differentiate N. coronata from N. sellnicki, like the number of setae on femora of adults and tritonymphs, the shape of insertions of prodorsal seta in and all gastronotal and adanal setae of juveniles; in N. sellnicki, these setae are inserted in small individual depressions, whereas in N. coronata, these depressions are absent. Our ecological observations confirm a common occurrence of N. coronata in raised bogs, a high percentage of juvenile stages in its populations and a preference of this species for humid microhabitats, whereas N. sellnicki is less common than N. coronata and occurs in drier habitats.

Ontogenetic instars of Zygoribatula excavata, with remarks on juveniles of Oripodoidea (Acari: Oribatida)

Information on the morphological ontogeny of oribatid mites of the family Oribatulidae is very scarce, and the juveniles of most species are unknown yet. In this work, the ontogenetic instars of the semicosmopolitan species, Zygoribatula excavata Berlese, 1916 are studied. The juvenile instars of this species are morphologically similar to those of the other species of Zygoribatula, and this genus can be included among those in which species are difficult to distinguish based on juvenile characteristics alone. As information on the morphological ontogeny of most species of Oribatulidae is still insufficient or unknown, a comparison on the juvenile characteristics of the families belonging to the superfamily Oripodoidea is given based on our own data and available literature sources. The major characteristics of juvenile instars of 10 families and 21 genera are presented. There are few characters, such as body shape and size, pattern of cuticle, excentrosclerites at gastronotic setae, size and morphology of setiform organs, such as bothridial as well as gastronotic setae that distinguish the families or genera of Oripodoidea.

Morphological ontogeny of Nanhermannia sellnicki (Acari, Oribatida, Nanhermanniidae), and comments on Nanhermannia Berlese.

The morphological ontogeny of Nanhermannia sellnicki Forsslund, 1958 is described and illustrated. In all juvenile stages the bothridial seta is minute, and two pairs of exobothridial setae are present (exa reduced to its alveolus, exp short). In the larva, the seta f1 is setiform but in the nymphs it is unobservable among cuticular tubercles. Most prodorsal and gastronotal setae of the larva are short while thouse of nymphs are long; seta in and all gastronotal and adanal setae are inserted in small individual depressions. In all instars the leg segments are oval in cross section and relatively thick, and most setae on tarsi are relatively short, thick or conical. The seta d accompanies solenidion on all genua, 1 on tibia I and on other tibiae.

Morphological ontogeny of Zachvatkinibates svanhovdi (Acari, Oribatida, Punctoribatidae).

The morphological ontogeny of Zachvatkinibates svanhovdi A. Seniczak & S. Seniczak, 2023 is described and illustrated. The juveniles of this species are light brown with slightly darker colour on the prodorsum, gastronotal shield, surrounding of gla opening, and legs. The larva has 12 pairs of gastronotal setae, most are of medium size and barbed; the nymphs have 15 pairs, most are short and smooth. In all juveniles, the setae of c-series are inserted on unsclerotized integument. In the larva, the pygidial shield is absent but, in the nymphs, the gastronotal shield is present and the setae p2 and p3 are inserted on unsclerotized integument. In the larva, a humeral organ is absent but is present in the nymphs.

Description of the ontogenetic changes in the morphology of Neoseiulus cucumeris (Acari: Phytoseiidae).

This paper reports the results of our studies of the morphological ontogeny of Neoseiulus cucumeris (Oudemans) based primarily on specimens reared in a laboratory at Manaaki Whenua Landcare Research, Auckland, New Zealand. We describe all postembryonic stages and illustrate them in detail: the larva, protonymph, deutonymph (male and female), and adult female and male.

Morphological ontogeny of Oribatula heterochaeta (Acari, Oribatida, Oribatulidae), with comments on some species of Oribatula Berlese.

The morphological ontogeny of Oribatula heterochaeta (Feider et al., 1970) is described and illustrated. The larva of this species has 12 pairs of gastronotal setae including h3 and the nymphs have 15 pairs; most are of medium size and barbed except for short and smooth h3 in the larva and p3 in the protonymph and deutonymph. In the larva, the excentrosclerites are present at four pairs of gastronotal setae (c2, la, lp, h1), and in the nymphs at seven pairs (c2, la, lp, h-series, p1). Comparisons of known morphological ontogeny of species in Oribatula are given.

Morphological ontogeny of Carinogalumna erciyesi sp. nov. (Acari, Oribatida, Galumnidae) from Turkey, with comments on Carinogalumna Engelbrecht.

The morphological ontogeny of Carinogalumna erciyesi sp. nov. from Turkey is described and illustrated. The adult of this species is most similar to that of C. montana Engelbrecht, 1973 but differs from it mainly by the shape of the bothridial seta and porose areas Aa and A2. The larva of C. erciyesi has 12 pairs of gastronotal setae, including alveolar h3, nymphs have 15 pairs; most setae are of medium size and barbed, except for short p2 and p3, smooth in protonymph; setae p2 and p3 are inserted on unsclerotized integument. In all juveniles the bothridial seta is clavate with long, narrow, barbed head. The gastronotal shield is well-developed with setae of d-, l-series and h1 in the larva, and of d-, l-, h-series and p1 in the nymphs. Setae of c-series of juveniles are inserted on microsclerites, and genital opening is placed on a large sclerite. In all juveniles a humeral organ is present, with porose area above it.

Morphological ontogeny of Eubelba danubedeltaica sp. nov. (Acari, Oribatida, Damaeidae) and comments on Eubelba Miko

The morphological ontogeny of Eubelba danubedeltaica sp. nov. is described and illustrated. The adult of E. danubedeltaica is most similar to E. sculpta (Mihelčič, 1957) which differs from E. danubedeltaica by the presence of tubercle E2p, slightly longer seta c1 and leg IV, and thicker and clearly barbed epimeral, genital, aggenital and anal setae whereas in E. danubedeltaica tubercle E2p is absent and these setae are thinner and most are smooth, except for finely barbed genital and anal setae that are clearly visible at a high SEM magnification. In the juveniles of E. danubedeltaica, most prodorsal setae are of medium size, except for short seta in in the nymphs and very long setiform bothridial seta which are strongly curved in the distal part. Most gastronotal setae of juveniles are long, or very long, except for medium-sized c3, la, lm and h2, and short h3 in the larva, and medium-sized c3 and p2 in nymphs. The nymphs are quadrideficient and eupheredermous, i.e. they have lost the d-series setae and carry the exuvial scalps of previous instars using a cornicle located between setal pair h3. In all juveniles, the famulus ɛ on tarsus I is sunken but is emergent in the adult. Seta d accompanies solenidion σ on genua I–III and φ on tibiae II–IV.

Morphological ontogeny of Pilogalumna ayildizi sp. nov. (Acari, Oribatida, Galumnidae), a new cryptic species from Turkey

The morphological ontogeny of Pilogalumna ayildizi sp. nov. is described and illustrated. This species is similar to P. tenuiclava (Berlese, 1908) as adult, but differs from it clearly by the morphology of juvenile stages and ecology. The larva of P. ayildizi has 12 pairs of gastronotal setae, most are short and smooth except for slightly longer dp and medium-sized c-series, h1 and h2, and minute h3, and the nymphs have 15 pairs of these setae, most are short and smooth except for medium-sized and barbed c-series. The gastronotal shield of juveniles is poorly developed with setae of d-, l-series and h1 in the larva, and d-, l-, h-series and p1 in the nymphs. In the juveniles setae of c-series, p2 and p3 have basal microsclerites, and a humeral organ is present.

Morphological ontogeny of Amerobelba decedens (Acari, Oribatida, Amerobelbidae)

The morphological ontogeny of Amerobelba decedens Berlese, 1908 is described and illustrated. In the adult of this species, the bothridial seta is setiform, unilaterally ciliate, notogastral setae are short and barbed, and sexual dimorphism is present on tarsus IV. Most prodorsal setae of juveniles are short and smooth, except for medium-sized ro, barbed in the nymphs. The bothridial seta is long, setiform and barbed in distal part. The gastronotal setae are of medium size and barbed, except for smooth c1 and c2 in all juveniles, and smooth of d-series and short h2 in the larva. Setae c1 and c2 are inserted on large macrosclerite, and other gastronotal setae are inserted on individual microsclerites, except for h2 in the larva. The anal and anogenital regions are reticulate, and adanal setae are inserted on individual microsclerites. The nymphs are quadrideficient and eupheredermous, i.e. they lose setae of d-series and carry the exuvial scalps of previous instars. In this species, seta d accompanies solenidion σ on genu III and φ on tibia III and IV, both in the juveniles and adults. It is a xero-thermophilous species, with one generation per year.

Morphological ontogeny of Pilogalumna kazakhstanica sp. nov. (Acari, Oribatida, Galumnidae) from Kazakhstan

The morphological ontogeny of Pilogalumna kazakhstanica sp. nov. from Kazakhstan is described and illustrated. The adult stage of this species is most similar to P. ornatula Grandjean, 1956, but differs from it mainly by slightly smaller body size and by having two postanal porose areas, whereas P. ornatula has usually a single porose area. In P. kazakhstanica the prodorsal porose area Ad and all notogastral porose areas are framed by dark brown integument, whereas in P. ornatula framed is usually porose area A1. The larva of P. kazakhstanica has 12 pairs of gastronotal setae, most are short and smooth, except for medium-sized and barbed c2, c3, h1 and h2, and minute, smooth h3, the nymphs have 15 pairs, most are short and smooth, except for medium-sized and barbed c2 and c3. In the juvenile instars the gastronotal shield is poorly developed, bearing setae of d-, l-series and h1 in the larva, and setae of d-, l-, h-series and p1 in the nymphs. In all juveniles, a humeral organ is present, and setae of c-, ad-series and p2 and p3 are with microsclerites.

Morphological ontogeny of Graptoppia granadaensis sp. nov. (Acari, Oribatida, Oppiidae), and comments on Graptoppia Balogh

The morphological ontogeny of Graptoppia granadaensis S. et A. Seniczak sp. nov. is described and illustrated, based on the instars obtained from laboratory cultures. The adults of this species were collected from spruce litter (Picea sp.) in the Campus of University of Science in Granada, Spain. These adults are the most similar to that of G. tanaitica Karppinen et Poltavskaja, 1990, but differ from it by having fewer spines on the bothridial seta. In laboratory cultures, G. granadaensis fed on deciduous and pine litter and small parts of pine cones, overgrown by mycelium. The juveniles of this species are unpigmented, with soft body, covered with microtuberculate cerotegument. The larva has 12 pairs of gastronotal setae, including h3, the nymphs have 15 pairs; all setae are smooth and mostly short. In the juveniles, seta d coupled to proper solenidia is present on genua I–III and tibiae II–IV.

Paedomorphosis and sexuality in Eulohmanniidae (Acari, Oribatida): surprising diversity in a relictual family of oribatid mites

The distinctive oribatid mite family Eulohmanniidae has been known almost exclusively from the type species of Eulohmannia, E. ribagai (Berlese, 1910), which is widely distributed in the northern Hemisphere where it inhabits fine humus, typically beneath forest litter and moss. We describe the morphological ontogeny of E. ribagai based primarily on material from New York—supported by specimens from Canada, Europe, and Asia—and correct errors in the literature. Ancillary biological notes relate to phenology, feeding biology, and reproduction; most important is the discovery of apparent sexual populations in the Pacific Northwest in this otherwise thelytokous (‘parthenogenetic’) species. Feeding seems to be preceded by secretion of a thick globule that captures food particles in the ventriculus, but this needs verification. Related nomenclatural actions include the clarification of purported synonyms and the proposal of species-rank for E. ribagai bifurcata Fujikawa. The latter was described as having several traits, including the purported presence of opisthonotal glands, that a study of type specimens show to reflect errors of observation or interpretation. A new diagnosis of Eulohmannia is informed also by preliminary observations on two as-yet undescribed species from Asia, one of which is apparently sexual, and the other paedomorphic in being monodactylous. We propose a new genus, Paedolohmannia n. gen., with P. metzi n. sp. as type, based on type material from Oregon, USA and additional material from California and Washington. The paraprocts of this species are formed by the adanal segment in all post-larval instars; it is only the second unequivocal example in Oribatida of the anal segment failing to appear during anamorphic development. This species also appears to be sexual, so it is unlikely that thelytoky was an ancestral trait of the family. Based on new information, the diagnosis for Eulohmanniidae is adjusted and expanded. Published inferences on the relationships of the family with other members of the paraphyletic infraorder Mixonomata, variously based on morphological and molecular methods, are reviewed and found inconsistent. While properly considered a relictual taxon, Eulohmanniidae is more diverse than previously thought, with the northeast Palaearctic and northwest Nearctic being regions especially deserving of more thorough sampling and genetic analysis.

Ontogenetic instars of Lepidacarus maafushiensis sp. nov. from the Maldives, with remarks on morphological ontogeny of Lohmanniidae (Acari, Oribatida).

Although the juvenile instars of oribatid mite family Lohmanniidae are well known compared to the other families of the infraorder Enarthronota, information on morphological ontogeny most known species is still lacking. Herein, a new species of the genus Lepidacarus is proposed from soil-litter of the Maafushi Island, Maldives, based on all ontogenetic instars. A comparative analysis of ontogenetic instars of species belonging various genera of Lohmanniidae is given, and the major characteristics of juvenile instars of 21 species are presented. From this analysis, it can be generalized that the juvenile morphologies of lohmanniid genera are quite similar and uniform, there is no significant features separating different genera of Lohmanniidae, and the juveniles of various genera differ from one another in the same characteristics as the adults.

Morphological ontogeny and complementary description of Neoseiulus subsolidus (Beglyarov) (Acari: Mesostigmata: Phytoseiidae)

The morphological ontogeny of Neoseiulus subsolidus (Beglyarov) (Acari: Mesostigmata: Phytoseiidae) was studied based on the specimens collected from Salix sp. (Salicaceae) leaves in Tyumen region and Altai Republic, Russia. All active life stages including larva, protonymph, deutonymph, adult female and male were described and illustrated. The taxonomic challenges in recognizing species in the canadensis species group are discussed.

Morphological ontogeny of Punctoribates ghilarovi (Acari, Oribatida, Punctoribatidae)

The morphological ontogeny of Punctoribates ghilarovi Shaldybina, 1969 is described and illustrated. This species is most similar to P. mundus Shaldybina, 1973, but is larger than the latter species. The juveniles of P. ghilarovi are light brown, with most prodorsal setae of medium size, except for long seta ro in the larva, and short and smooth seta ex in all instars. The larva has 12 pairs of gastronotal setae, including h3, the nymphs have 15 pairs. Most of them are medium sized and barbed, except for slightly longer dm, dp, lm, lp and h1, and short and smooth h3 in the larva, and short and smooth da and dm, slightly longer dp, and clearly longer h1, h3 and lp in the nymphs. In all juveniles, a humeral organ is present.