Ventral Rows Research Articles

The rediscovery of Epigomphus sulcatistyla Donnelly, 1989, with a description of its larva and female (Odonata: Gomphidae)

The larva of Epigomphus sulcatistyla Donnelly, 1989 is described, figured and compared with other described Mexican larvae. It is characterized by 3rd antennomere spindle-shaped, almost twice longer than its widest part; ligula with a ventral row of eight short, truncate teeth on middle; abdomen lateral spines on S7–9 slightly divergent; male epiproct dorsal tubercles rounded apically and divergent distally. It differs from other Mexican species mainly in shape of 3rd antennomere, number of teeth on ligula, serrations on lateral margins of S8–9, and shape of cerci. Also, the hitherto unknown female is described, for the first time, based on four teneral female from reared larvae.

Polysporangiate anthers described in Eugenia (Myrtaceae) with notes on evolutionary patterns

Shifts towards compartmentalisation resulting in multilocular anthers have been described in some families of Myrtales but to date, not in Myrtaceae. In these other families sporogeneous tissue is partitioned by transverse or longitudinal septa, fitting the definition of the ‘polysporangiate anther’. Polysporangiate anther in Eugenia, a Neotropical genus of Myrtaceae is here discussed, with a detailed description of their morphology and in the context of known phylogenetic relationships within Eugenia. Anthers of Eugenia joseramosii, E. kerianthera and E. petaloidea were examined using scanning electron microscopy; E. multilocellata and E. quilombola were imaged with light microscope. Molecular sequences of five regions were used to place these species in a representative phylogenetic framework for character reconstruction analysis. Analysed anthers share dithecal organization in which each anther theca is divided in dorsal and ventral rows of sporangia. Polysporangiate anthers in Eugenia appear to have evolved independently on at least two occasions in Eugenia sect. Umbellatae. Eugenia flowers with polysporangiate anthers fit a generalist pollination pattern but Eugenia petaloidea demonstrates some unusual features that may be linked to pollination by vibration. Anthers in Eugenia is a rare condition with low systematic value. Resources should be invested to survey Myrtaceae for more species with polysporangiate anthers, to improve understanding of their evolutionary relevance and to record pollinators and modes of pollination.

New record of a mantis-like dictyopteran from the Lower Cretaceous Crato Formation (Brazil)

We present a new fossil representative of Dictyoptera (the group includes the modern Mantodea and Blattodea) from the Lower Cretaceous Crato Formation (Brazil). LP/UFC CRT 2221(a,b) is characterized by head orthognathous, antennae filiform, large eyes situated laterally, prothorax short, abdomen stout, raptorial forelegs folded and robust, at least prefemora with ventral row of spines and forewings tegminous protrude beyond the abdomen. The shape of the prothoracic appendage and its articulations indicate that the tibia opposes the femur as in most mantodeans. However, the shape and dimensions of the coxae and venation pattern in the apical part of the wing are commonly associated to blattodeans. Unfortunately, the preservation of the wing venation in the here described specimen is incomplete, which prevents a reliable and objective reconstruction of the exact venation pattern. Many species descriptions of fossil dictyopterans are mostly based on the wing venation, consequently, it is difficult to determine its taxonomic status. Although the incompleteness of the specimen does not allow for a formal description, the overall characteristics are consistent with primitive mantodean-type insects. Fossil representatives of transitional forms or side branch groups are rather scarce in the fossil record. Therefore, the specimen presented here may contribute to a better understanding of evolutionary events within Dictyoptera during the Cretaceous.

A new species of Dixonius (Squamata: Gekkonidae) from Vientiane Capital, Laos.

A new species of the gekkonid genus Dixonius is described from Huaysorn-Huaysua village, Nasaithong District, Vientiane Capital, Laos. The new species can be distinguished from all other species by a combination of the following characters: maximum SVL 47.1 mm; 1921 longitudinal rows of dorsal tubercles at midbody; 2326 longitudinal rows of ventrals across the abdomen; 7 or 8 supralabials, 6 in mid-orbital position; 5 or 6 infralabials; 5 or 6 precloacal pores in males, femoral pores lacking; precloacal and femoral pores absent in females; a canthal stripe running from rostrum through the eye and terminating at back of head; dorsum brown with irregular dark marks. In phylogenetic analyses, the species is recovered as the sister taxon to D. siamensis, which occurs in Laos, Thailand, and Vietnam. Genetically, the two species are approximately 9.4% divergent from each other based on the complete mitochondrial ND2 gene with six partial or complete adjacent tRNAs. It is the 12th species known in the genus Dixonius and the second Dixonius species described from Laos.

Morphology and ontogenesis of two new Hemiholosticha species (Ciliophora, Hypotrichia, Hemiholostichidae nov. fam.)

The morphology and ontogenesis of two new hypotrich ciliates, Hemiholosticha solitaria and Hemiholosticha germanica, were studied using live observation, protargol impregnation, and scanning electron microscopy. Both species share a medium-sized, almost globular body with a short anterior projection; two macronuclear nodules with a single micronucleus in between; a central contractile vacuole; three or four ventral, one postoral, one right and one left marginal cirral row; and three dorsal kineties extending along ribs. However, H. germanica is distinguished from congeners by a higher number of cirri in ventral rows R1 and R2 (3–6 vs. 2 cirri in each row). Hemiholosticha solitaria differs from congeners by having four (vs. three) ventral cirral rows and by the lack (vs. presence) of intracellular green algae. The ontogenesis of H. solitaria follows the H. pantanalensis mode in that (i) the oral primordium develops in a deep pouch and generates the first two cirral streaks in addition to adoral membranelles and undulating membranes, (ii) the undulating membrane anlage does not produce any cirri, and (iii) the longitudinal ventral cirral row R3 originates from two anlagen. The ontogenetic peculiarities along with the 18S rRNA gene phylogenies suggest classification of Hemiholosticha, Psilotrichides, and Urospinula into a new family, Hemiholostichidae.

Scale performance and composition in a small Amazonian armored catfish, Corydoras trilineatus

The cory catfishes (Callichthyidae) are small, South American armored catfishes with a series of dermal scutes that run the length of the fish from posterior to the parieto-supraoccipital down to the caudal peduncle. In this study, we explore the anatomy and functional performance of the armored scutes in the three-striped cory catfish, Corydoras trilineatus. The lateral surface has a dorsal and a ventral row of scutes that interact at the horizontal septum. The scutes have little overlap with sequential posterior scutes (~33% overlap) and a deep ridge in the internal surface that connects to the underlying soft tissue. The internal surface of C. trilineatus scutes is stiffer than the external surface, contrary to the findings in a related species of cory catfish, C. aeneus, which documented a hypermineralized, enamel-like, non-collagenous, hyaloine layer along the external surface of the scute. Clearing and staining of C. trilineatus scutes revealed that the scutes have highly mineralized (~50% mineralization) regions embedded in between areas of low mineralization along the posterior margin. Puncture tests showed that posterior scutes were weaker than both anterior and middle scutes, and scutes attached to the body required 50% more energy to puncture than isolated scutes. Corydoras trilineatus has the strongest armor in areas critical for protecting vital organs and the external armored scute receives synergistic benefits from interactions to the soft underlying tissue, which combine to provide a tough protective armor that still allows for flexible mobility.

Redescription of Apobaetis lakota McCafferty, 2000 (Ephemeroptera: Baetidae) and description of two new species from Brazil.

The genus Apobaetis Day is known by its small size and larval shifting-sand habitat preference (psammophilous). Three species of this genus are recorded in North America, from these, only Apobaetis lakota McCafferty needs to be redescribed because its original description is incomplete, turning difficult to distinguish it from species with similar morphology. Therefore, one of the objectives of this study is to redescribe A. lakota. Based on this redescription, two new species from Brazil, with similar morphology could be identified and are described (Apobaetis biancae sp. nov. and Apobaetis jacobusi sp. nov.). Apobaetis lakota can be differentiated by the labrum rectangular, distal margin without medial emargination, medial area of distal margin with three sockets of setae on dorsal surface; maxillary palp long, more than 2.0× the length of galea-lacinia, segment I with the same length as galea-lacinia; lingua subcircular with one medial lobe; glossa distally rounded; inner projection of labial palp segment II rounded and distally directed, segment III triangular; tarsal claws 1.3× the length of tarsus, without row of denticles. Apobaetis jacobusi sp. nov. can be differentiated from other species by fore tarsal claw I with the same length of tarsus, labrum medially with two protuberances and glossa with pointed apex. Apobaetis biancae sp. nov. can be differentiated by the absence of a ventral row of long thin setae near distolateral margin of labrum, four marginal spines on the paraproct, a subrectangular hypopharynx, and by the absence of robust setae on inner margin of the glossa.

A new leaf-toed gecko (Gekkonidae: Dixonius) from the city of Ranong, southwestern Thailand.

We describe Dixonius dulayaphitakorum sp. nov. from Ranong city, Ranong Province, southern peninsular Thailand. The new, ground-dwelling species differs from all currently recognized Dixonius by a combination of morphological characters and pattern: maximal known SVL of 47.8 mm, 22 longitudinal rows of dorsal tubercles; 33 to 35 paravertebral scales; 22 longitudinal rows of ventrals across the abdomen; six or seven precloacal pores in males, no pores in females; no distinct canthal stripe; and a spotted dorsal pattern. Based on dorsal pattern, the new species seems related to Dixonius siamensis. This description brings to 11 the number of Dixonius species, and to five the ones endemic to Thailand.

Ontogeny and potential function of poacher armor (Actinopterygii: Agonidae).

Many vertebrates are armored over all or part of their body. The armor may serve several functional roles including defense, offense, visual display, and signal of experience/capability. Different roles imply different tradeoffs; for example, defensive armor usually trades resistance to attack for maneuverability. The poachers (Agonidae), 47 species of scorpaeniform fishes, are a useful system for understanding the evolution and function of armor due to their variety and extent of armoring. Using publically available CT-scan data from 27 species in 16 of 21 genera of poachers we compared the armor to axial skeletal in the mid body region. The ratio of average armor density to average skeleton density ranged from 0.77 to 1.17. From a defensive point of view, the total investment in mineralization (volume * average density) is more interesting. There was 10 times the material invested in the armor as in the endoskeleton in some small, smooth plated species, like Aspidophoroides olrikii. At the low end, some visually arresting species like Percis japonica, had ratios as low as 2:1. We categorized the extent and type (impact vs. abrasion) in 34 Agonopsis vulsa across all 35+ plates in the eight rows along the body. The ventral rows show abrasive damage along the entire length of the fish that gets worse with age. Impact damage to head and tail plates gets more severe and occurs at higher rates with age. The observed damage rates and the large investment in mineralization of the armor suggest that it is not just for show, but is a functional defensive structure. We cannot say what the armor is defense against, but the abrasive damage on the ventrum implies their benthic lifestyle involves rubbing on the substrate. The impact damage could result from predatory attacks or from intraspecific combat.

A new species of Dixonius (Squamata: Gekkonidae) from the karst forest of Khammouane Province, central Laos

A new species of Dixonius is described on the basis of three specimens from the karst forests around Thakhek town, Khammouane Province, Laos. The new species from Laos can be distinguished from other species of Dixonius based on molecular and morphological divergences. It is characterized by a maximum SVL of 55.4 mm; 20-23 longitudinal rows of dorsal tubercles at mid-body; 23-24 longitudinal rows of ventrals across the abdomen; 8-10 supralabials, 7 or 8 in mid-orbital position; 7 or 8 infralabials; 8 precloacal pores in male; the male without femoral pores; precloacal and femoral pores absent in females; uniformly pebble brown dorsum. In phylogenetic analyses, the new species is shown to be the sister taxon to two undescribed taxa from Thailand but differs by at least 8.6% in genetic pairwise distance from the latter based on the complete sequences of the mitochondrial ND2 gene with partial or complete sequences of six adjacent tRNAs. This is the ninth known species of Dixonius, and the second recorded species from Laos.

Scelidosaurus harrisoniifrom the Early Jurassic of Dorset, England: the dermal skeleton

<i>Scelidosaurus harrisonii</i>from the Early Jurassic of Dorset, England: the dermal skeleton

Reevaluation of the ‘well-known’ Paraurostyla weissei complex, with notes on the ontogenesis of a new Paraurostyla species (Ciliophora, Hypotrichia)

Two hypotrichous ciliates, Paraurostyla wuhanensis nov. spec. from Wuhan (China) and a new North American population of the Paraurostyla weissei complex, were studied based on live observations and protargol impregnation. Paraurostyla wuhanensis nov. spec. differs from the congeners by the combined features of having six or seven frontal cirri, 2–4 frontoventral cirri, 5–7 ventral rows, and yellow-greenish cortical granules. Ontogenesis proceeds as in the type species, except that fewer frontoventral cirri are formed in the new species. The morphology of the new population of the Paraurostyla weissei complex corresponds well with other American populations. In the phylogenetic trees based on the 18S rRNA gene, Paraurostyla sequences nest in a large clade together with Apoamphisiella and Notohymena. Monophyly of Paraurostyla is rejected by the results of the approximately unbiased test analyses. Morphological, morphogenetic, and phylogenetic analyses show a close relationship between the North American populations of the Paraurostyla weissei complex and Apoamphisiella, indicating that the taxonomic position of the former needs to be reassigned. A new combination, viz. Apoamphisiella polymicronucleata (Merriman, 1937) comb. nov., a reevaluation of the Paraurostyla weissei complex, and emended diagnoses of Paraurostyla and Apoamphisiella, are provided.

Some features of embryonic development of eggs and larvae of three stripe rockfsh Sebastes trivittatus (Sebastidae) at Primorye (Japan Sea)

Later embryonic development ofSebastes trivittatuspasses in 20 days under water temperature 10 оС (in June-July). During this period, the embryos ofS. trivittatusincrease in diameter from 0.1 mm to 1.3 mm and change their shape from spherical to elliptical. Within gonads of pre-hatching females, the embryos have different stages: from prelarvae on late stages of development in the internal layers to pre-hatching larvae in the external layer. The pre-hatching larva hasTL4.1 mm, 5–6 melanophores on the top of head, 20 melanophores in ventral row, some melanophores on peritoneum, and oil globule in the frontal part of intestine; its notochord is not flexed, yolk sac is absent, body myotomes are poor visible, number of tail myotomes is 24.

A new skink of the genus Sphenomorphus Fitzinger, 1843 (Squamata: Scincidae) from Hon Ba Nature Reserve, southern Vietnam.

A new forest skink of the genus Sphenomorphus Fitzinger, 1843 is described from Khanh Hoa Province, southern Vietnam based on morphological characters of four specimens and a fragment of 653 nucleotides of the gene COI. Sphenomorphus yersini sp. nov. is characterized by the following morphological characters: medium size in adults (snout-vent length up to 55 mm); tail length/snout-vent length ratio 1.81; toes reach to fingers when limbs adpressed; midbody scale rows 32-34, smooth; paravertebral scales 61-69; ventral scale rows 58-67; subcaudal scales 112; supraoculars four, rarely five; prefrontals in broad contact with one another; loreal scales two; tympanum deeply sunk; smooth lamellae beneath finger and toe IV 10-12 and 18-20 respectively; a pair of enlarged precloacal scales; hemipenis deeply forked and asymmetrical with two differently sized smooth lobes. The new species differs from its most similar congener, Sphenomorphus buenloicus Darevsky Nguyen, 1983, by 16.4-16.7% uncorrected p-distance in COI sequences.

Combining morphological and molecular data to classify Laxus sakihariiae sp. n., a new stilbonematine nematode (Nematoda: Desmodoridae) from the coast of Sesoko Island, Japan

Because of their relatively simple body plan, the number of morphological characters used to differentiate between closely related nematode genera is often limited. In addition, boundaries among genera sometimes become blurred due to the appearance of new trait combinations as more new species are described. Molecular phylogenetic analyses can address the shortcomings of morphological taxonomy by clarifying relationships among closely related species and genera and can help identify which morphological characters are taxonomically informative. Here, we describeLaxus sakihariiaesp. n. from shallow subtidal sands on Sesoko Island in the Okinawa prefecture, investigate phylogenetic relationships with other stilbonematine species and genera based on SSU rDNA sequences, and provide the first LSU rDNA sequence for the subfamily. The new species can be easily distinguished from all other species of the genus by the presence in the male of subventral and ventral rows of stout and spine-like setae in the pre- and postcloacal regions. This feature suggests affinities with the closely related genusLeptonemella, although the SSU consensus tree clearly shows that the new species forms a monophyletic clade together with the otherLaxusspecies for which sequences are available. The structure of the cephalic capsule inL. sakihariiaesp. n., which consists of a block layer between the median and basal zones of the cephalic cuticle, is consistent with the placement of this species. This trait is not currently used as a diagnostic feature, but our finding suggests that the structure of the cephalic capsule may be taxonomically useful for differentiating between some stilbonematine genera.

Occurrence of a leafy Jungermanniales in the Mesozoic of the Rajmahal Hills, India

A member of leafy Jungermanniales of Hepaticopsida is seen in a thin section prepared of silicified chert of Nipania, Rajmahal Hills, Jharkhand. The leafy thallii are either simple or bifurcated and have two lateral rows and one ventral row of leaves. Young plant has only few leaves. Multicellular ventral scales resembling those of extant Marchantiales are also seen in the slide. Scattered spores of pteridophytes and pollen grains of gymnosperms are also visible. Occurrence of a fossil leafy Jungermanniales plant is reported for the first time from this fossiliferous area.

MtDNA differentiation and taxonomy of Central Asian racerunners of Eremias multiocellata-E. przewalskii species complex (Squamata, Lacertidae)

We provide an integrative analysis of the diversity of the E. multiocellata—E. przewalskii species complex in Central and Middle Asia using morphological and molecular (COI DNA-barcoding) data. We report preliminary data on mtDNA variation within this group and clarify the taxonomic status and distribution of the members of the species complex. We also provide a description of a new Eremias species from Eastern Kazakhstan and western Mongolia, where it occurs in sympatry with E. multiocellata sensu stricto, from which it can be clearly differentiated using both morphological and molecular characters. The new species, described as Eremias dzungarica sp. nov., is assigned to the subgenus Pareremias on the basis of the following features: subocular not reaching mouth edge; one frontonasal; two supraoculars; the row of small granular scales between supraoculars and frontal with frontoparietals absent; distance between the femoral pore rows being wide; femoral pore rows not reaching knee-joint; coloration pattern with light colored ocelli with black edging. The new species can be distinguished from its congeners on the basis of the following morphological attributes: a medium-sized lacertid lizard, maximum snout-vent length (SVL) = 64.5 mm, tail being ca. 1.5 times longer than body length (SVL), hindlimbs relatively long (hindlimb length to SVL ratio 0.46); subocular scale not reaching mouth edge, in touch with 6–8 supralabials; males with bright coloration consisting of 2–3 dorsolateral rows of light-colored ocelli with thick black edging; the ventral row of ocelli in life is greenish to bluish; dorsal pattern consisting of black irregular blotches along the middorsal line. We also report on the high genetic and morphological diversity of E. multiocellata in Mongolia and China, synonymize E. m. bannikowi with the nominative form E. m. multiocellata, discuss variation within E. przewalskii, synonymize E. p. tuvensis with the nominative form E. przewalskii, provide new data on E. cf. reticulata and E. m. tsaganbogdensis, confirm validity and clarify distribution ranges of E. stummeri, E. szczerbaki and E. yarkandensis and discuss further progress on taxonomic studies of the E. multiocellata—E. przewalskii species complex.

A new limestone-dwelling leaf-toed gecko (Gekkonidae: Dixonius) from Khao Sam Roi Yot massif, peninsular Thailand.

We describe Dixonius kaweesaki sp. nov. from Khao Daeng, a limestone mountain in Khao Sam Roi Yot massif, Prachuap Khiri Khan Province, peninsular Thailand. It is diagnosed from all other species by a combination of maximal SVL of 41.6 mm; 12 or 13 longitudinal rows of dorsal tubercles; 24 longitudinal rows of ventrals across the abdomen; a continuous series of 9-11 precloacal pores in males, no pores in females; and two bold dark stripes from the snout to the base of the tail separated by a contrasting light vertebral stripe. It is the eighth species in the genus Dixonius. Lastly, we discuss the type locality of Phyllodactylus paviei, currently regarded as a junior subjective synonym of Dixonius siamensis.

Argyripnus boreopacificus sp. nova, a new species of hatchetfishes (Sternoptychidae) from the subtropical Northwestern Pacific

A new species of the genus Argyripnus is described from the underwater elevations of the Northwestern Pacific. The species is most similar to A. hulleyi from the western Indian Ocean, but it differs in a larger number of rays of the dorsal and pectoral fins, a slightly larger number of photophores in the ventral row, and several other characters. The type series of the species is the most northern record of the representatives of the genus in the Pacific Ocean.

The ammonoid genus Spiroceras (Spiroceratidae, Ammonoidea) from the Upper Bajocian of the Northern Caucasus

Ammonites of the genus Spiroceras are described from the Upper Bajocian of the Kyafar River Basin (Karachay-Cherkessia), including macroconchs with preserved apertures and (for the first time in the entire history of the study of Middle Jurassic heteromorphs) microconchs with lateral lappets. The microconchs of S. bispinatum (Baugier et Sauze), mainly represented by cyrtocones with one ventral row of nodes, correspond to microconchs with a gyroconic shell and a single row of nodes. Macroconchs and microconchs of S. annulatum (Deshayes), the ribs of which lack prominent nodes or spines, are found together. The assemblage also contains small-sized slightly uncoiled shells of Spiroceras aff. S. fourneti Roman et Petouraud with widely spaced ribs and two prominent rows of large nodes, presumably macro- and microconchs. The ornamentation of this species resembles that of the monomorph Bajocia rarinoda Sturani from the upper part of the Lower Bajocian; perhaps the latter was ancestral to the Middle Jurassic heteromorph. The above species of Spiroceras, as well as S. obliquecostatum (Quenstedt), are figured.