Integrative description of a new species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Shennongjia, Central China.

A new species of the genus Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Xiangxi River, Shennongjia Forestry District, Hubei Province, China, is described on the basis of an integrative approach, involving morphology, and molecular systematics. The new species Dugesia saccaria A-T. Wang & Sluys, sp. nov. is characterized by the following features: a dumb-bell-shaped, muscularized hump located just anterior to the knee-shaped bend in the bursal canal; a ventrally displaced ejaculatory duct, which, however, opens terminally through the dorsal portion of the blunt tip of the penis papilla; a ventrally located seminal vesicle, giving rise to a vertically running duct that eventually curves downwards to communicate with the ejaculatory duct via a small diaphragm; oviducts opening asymmetrically into the dorsal portion of the common atrium and at the knee-shaped part of the bursal canal. The phylogenetic position of the new species was determined using four molecular markers (18S rDNA; ITS-1; 28S rDNA; COI), which suggested that it groups with other species of Dugesia from the Australasian and Oriental biogeographical regions.

The complete mitochondrial genome of a marine triclad Miroplana shenzhensis (Platyhelminthes, Tricladida, Maricola).

The complete mitochondrial genome (mitogenome) of Miroplana shenzhensis Yu & Wang, 2013 is reported in the present study, representing the second mitogenome recorded in the suborder Maricola. The circular mitogenome is 14,344 bp in length, containing 12 protein-coding genes, 2 ribosomal RNAs and 22 transfer RNAs. Comparative analysis on mitochondrial gene order reveals a rearrangement in the suborder Maricola, indicating that mitochondrial gene order is conserved only in Continenticola, and is divergent across Tricladida. Phylogenetic analysis shows M. shenzhensis is clustered with an another marine triclad, forming a well-supported monophyletic group of Maricloan.

A New Species and New Record of Freshwater Turbellarians of the Genus Gieysztoria (Platyhelminthes: Rhabdocoela) from China.

A new species of Dalyelliidae, Gieysztoria pellucida Wang and You, is described based on material collected in southern China through an integrative approach combining morphological, histological, and molecular (18S and 28S rDNA) data. Gieysztoria pellucida sp. nov. is morphologically characterized by a fan-shaped (about 270° when pressed) stylet, consisting of 13 similar distal spines and a broad girdle without fenestrae region. This stylet is distinct from that of any other similar species in the Aequales group to which this species belongs. In addition, specimens identifiable as Gieysztoria garudae Van Steenkiste, Van Mulken, and Artois, 2012 were discovered from the same location as G. pellucida sp. nov. Gieysztoria garudae has previously been known only from India; the present study thus represents the first record of the species from China.

MitoFlex: an efficient, high-performance toolkit for animal mitogenome assembly, annotation and visualization.

SUMMARY: MitoFlex is a linux-based mitochondrial genome analysis toolkit, which provides a complete workflow of raw data filtering, de novo assembly, mitochondrial genome identification and annotation for animal High Throughput Sequencing data. The overall performance was compared between MitoFlex and its analogue MitoZ, in terms of protein-coding gene recovery, memory consumption and processing speed. AVAILABILITYAND IMPLEMENTATION: MitoFlex is available at https://github.com/Prunoideae/MitoFlex under GPLv3 license. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Two new species of a new genus, Pseudorogneda, of Polycystididae discovered in Southern China.

Two new species of the new genus Pseudorogneda of Polycystididae were discovered in a brackish environment from Southern China. Pseudorogneda sinensis n. gen. n. sp., is distinguished by a semicircular double-walled prostate stylet type II that tapers in diameter from proximal to distal with a proximal-to-distal fold, and an inner wall with a funnel-shaped base originating at the midpoint of the outer wall; its flattened tubular prostate stylet type IV exhibits a horn-like base and a proximal-to-distal folded structure on its wall. For Pseudorogneda shenda n. gen. n. sp., its crescent-shaped prostate stylet type II is double-walled and the inner wall has a funnel-shaped base that starts at the proximal 2/3 position of the outer stylet and is fused with the outer stylet to form a sharp distal end; its tubular and slightly-curved prostate stylet type IV exhibits a slit and a distal fold. Phylogenetic analysis of 18S rDNA and 28S rDNA sequences shows that the two novel species are clustered to form an independent clade from other genera, which is consistent with morphological comparison in the establishment of two new species in a new genus.

Two new species of marine flatworm from southern China facilitate determination of the phylogenetic position of the genus Nerpa Marcus, 1948 and the histochemical structure of the nervous system in the genus Paucumara Sluys, 1989 (Platyhelminthes, Tricladida, Maricola).

Two new species of flatworm, collected from a beach at eastern Shenzhen, China, were studied through an integrative approach by combining morphological, histological, histochemical (acetylcholinesterase, AChE), and molecular (18S r- DNA) data. These species belong to two genera of marine triclads, previously unrecorded from China, viz. Nerpa Marcus, 1948 and Paucumara Sluys, 1989.        Nerpa fistulata Wang Chen, sp. nov. is characterized by: transparent body; principally pentamerous intestine with three distinct commissures; two very large, prepharyngeal testis follicles; a semi-circular lens in each eye cup; a penis papilla provided with a chitinized, pointed stylet; lateral bursae communicating with the oviduct and opening ventrally to the exterior via a duct. Phylogenetically N. fistulata groups with one member of the family Bdellouridae. This new, Chinese species of Nerpa introduces a major geographic disjunction, as the type species N. evelinae was described from the bay of Santos, Brazil, so that the genus is now known from both Atlantic as well as Pacific coasts.        The species Paucumara falcata Wang Li, sp. nov. is characterized by: three distinct pale yellow transverse pigmentation bands on its dorsal side, between which some snowflake-like specks are randomly distributed, and a brown transverse band anteriorly to the eyes; 8-11 testicular follicles on either side of the body, the follicles extending from immediately behind the ovaries to half-way along the pharyngeal pocket; a musculo-parenchymatic organ with a sclerotic, curved tip projecting from the anterior wall of the male atrium, ventrally to the root of the penis papilla. Phylogenetically P. falcata groups with its congener P. trigonocephala, with the genus Paucumara forming the sister taxon of the genus Ectoplana. Comparison of the nerve structure of P. falcata, as revealed by AChE histochemistry, with that of eight other species of triclad suggested that the nervous system of marine planarians is simpler than that of species of freshwater planarians, but revealed also that the nerve structure is rather variable among species.        The copulatory position exhibited by two partners in Paucumara falcata is remarkable in that they intertwine, with their heads pointing downwards and the tails pointing upwards, the entire process lasting about 10 min. Such a copulatory position has never before been reported for triclad flatworms.

Two new brackish-water species of Pogaina (Rhabdocoela: Provorticidae) from China.

Two new species of the genus Pogaina Marcus, 1954 (Provorticidae), namely Pogaina sinensis n. sp. and Pogaina shenzhenensis n. sp. are described from brackish water in the intertidal zone of Shenzhen Bay. For P. sinensis n. sp., the tubular stylet is slightly curved at the distal end and a fusiform structure with a flange is present at 66% of the stylet. The flange encircles the stylet, with its ends attached to the midpoint and the distal end of the stylet. For P. shenzhenensis n. sp., the stylet has a N-shaped overall morphology. A band provided with dense needle-like structures is present at the distal end of the stylet. Both the morphological (stylet) and phylogenetic (18S rDNA and 28S rDNA) analyses support the establishment of these two new species.

Two new species of Rhabdocoela (Polycystididae and Trigonostomidae) from China.

Two new species of Rhabdocoela, namely Alcha sinensis n. sp. (Polycystididae) and Trigonostomum sinensis n. sp. (Trigonostomidae), were discovered from the intertidal zone of eastern Shenzhen City, China. For A. sinensis n. sp., the stylet consists of two symmetrical triangular plates and one lamellar plate. All three plates are jagged at their posterior ends. The anterior end of the stylet connects to a thick muscular layer, which causes its movement. For T. sinensis n. sp., the copulatory organ consists of a long-tubular stylet and two "T"-shaped plates (plate I and plate II). The stylet bends 120° at 25% of its length from the base and extends straight distally. Two "T" plates are connected to each other and surround the stylet. Plate I is hook-shaped at its distal end, and plate II has a similar length but only half the width of plate I. The phylogenetic (18S rDNA and 28S rDNA) results also support the establishment of these two new species. On the basis of the molecular phylogeny and morphology of the copulatory organ and bursa appendage, we propose a new categorization of the species of Trigonostomum.

Macrostomum shenda and M. spiriger, two new brackish-water species of Macrostomum (Platyhelminthes: Macrostomorpha) from China.

In this study, two new brackish-water species of Macrostomum (M. shenda n. sp. and M. spiriger n. sp.) collected from Shenzhen, China, were described based on morphological, histological, and molecular phylogenetic analyses. Macrostomum shenda n. sp. differs from its congeners in the oblique and non-thickening distal opening of its narrow funnel-shaped stylet. In addition, its sperm have neither bristles nor brush, and are surrounded by an undulating membrane in the mid-body region. In M. spiriger n. sp., the stylet is spirally twisted. Its reproductive apparatus has a seminal bursal pore opening exteriorly. Results of the 18S and 28S rDNA phylogenetic analyses also support the establishments of these two new species. Moreover, the 18S and 28S rDNA sequences of some species within Macrostomum in previous studies have been revised to avoid ambiguity, while Macrostomum dongyuanensis Wang Sun, 2015 was re-identified as a new record of M. quiritium Kolasa, 1973 from China.

A new species and new record of Polycystididae (Rhabdocoela: Kalyptorhynchia) from China.

One new species and one newly recorded species of Polycystididae from China, Paulodora sinensis n. sp. and Polycystis ali Schockaert, 1982, were described based on comprehensive morphological and molecular analyses. In Paulodora sinensis n. sp., the stylet is double-walled and is composed of a funnel-shaped proximal part and a spiral distal part, while the outer stylet forms a minor fold proximally. In Polycystis ali Schockaert, 1982, the stylet is also double-walled with a funnel-shaped proximal part. However, the collar-shaped distal part is partially concave and forms a jagged edge. The concatenated 18S rDNA and 28S rDNA phylogenetic analysis supports the establishment of the new species. Besides, based on the morphology of stylet, we have made detailed categorization among the recorded species within these two genera.

Two new species and the molecular phylogeny of eight species of Macrostomum (Platyhelminthes: Macrostomorpha) from southern China.

Two new species of Macrostomum (Platyhelminthes: Macrostomorpha), M. shiyanensis n. sp. and M. lankouensis n. sp. are described from Shiyan Reservoir and Lankou Town. Morphological characteristics of the penis stylets and sperm, as well as the phylogenetic analysis using concatenated sequences of 18S and 28S rDNA genes support the establishment of these two new species and indicate that they are closely related to M. sinensis and M. heyuanensis described from different regions of Guangdong province. Finally, the progress of molecular phylogenetics of Macrostomum worldwide is also discussed.

Two new species of Kalyptorhynchia (Koinocystididae and Gnathorhynchidae) from China.

Two new species of Kalyptorhynchia (Rhabdocoela), namely Itaipusa sinensis n. sp. (Koinocystididae) and Prognathorhynchus sinensis n. sp. (Gnathorhynchidae) were described from brackish water near Shenzhen Bay, representing the first records of Koinocystididae and Gnathorhynchidae in China. For I. sinensis n. sp., the U-shaped cirrus contains 50 triangular lamellar spines, with two cuticular (pseudocuticular) hooks situated at both sides of its anterior part. The hook I (right side) is funnel-shaped, while the hook II (left side) is triangular lamellar in shape. For P. sinensis n. sp., the proboscis hook has two hooks situated in an anterior to posterior sequence. The semicircular tubular stylet has a hollow spherical dead end posteriorly to the distal opening. Both the morphological and phylogenetic (18S rDNA and 28S rDNA) analyses support the establishment of these two new species.

Two new brackish-water species of Macrostomum (Platyhelminthes, Macrostomida) from mangrove wetland in southern China.

In this paper, two new brackish-water species of Macrostomum (M. shenzhenensis n. sp. and M qiaochengensis n. sp.) collected from the artificial lake in Overseas Chinese Town mangrove wetland, are described based on the morphology of the penis stylet and on a molecular phylogenetic analysis. M. shenzhenensis n. sp. has an elongate, narrow stylet with torus-shaped distal wall thickening, while M. qiaochengensis n. sp. has a hook-like stylet with a pointed end. Both the 18S and 28S rDNA phylogenetic analyses of M shenzhenensis n. sp. and M qiaochengensis n. sp. support the establishments of these two new species. Finally, categorization of these two new species based on the morphology of sperm and penis stylet, as well as other morphological features of the reproductive system is briefly discussed.

A new species of the genus Bothrioplana (Platyhelminthes: Bothrioplanida: Bothrioplanidae) and a new species of the genus Pentacoelum (Tricladida: Bdellouridae) from southern China.

Two new species of turbellarians, Bothrioplana sinensis n. sp., and Pentacoelum sinensis n. sp., were described based on their reproductive behavior, ontogenic development, morphology in whole-mounted and sectioned specimens, and 18S rDNA phylogenetic classification. Bothrioplana sinensis n. sp. represents a newly recorded order in China and the second identified species in the genus Bothrioplana. It is characterized by a pair of spherical-shaped well-developed testes located dorsally behind the pharynx, and the common vas deference located ventrally to the gonopore. Phylogenetic analysis showed that this new species is closely related to parasitic flatworms. Pentacoelum sinensis n. sp. is characterized by two uteri instead of lateral bursae located laterally near the tail end and a lack of connection between the posterior intestinal branches. Each uterus has a ventral receptaculum seminalis (also functioning as bursa copulatrix) which has a muscular vagina externa opening obliquely to the ventral side at the tail end.

Two new species of brackish-water Macrostomum (Platyhelminthes, Macrostomida) from southern China.

Two new species of brackish-water Macrostomum (M. zhujiangensis n. sp. and M. baoanensis n. sp.) were described based on samples collected from the littoral zone of the Zhujiang Estuary. These are the first records of brackish-water Macrostomum from southern China. Macrostomum zhujiangensis n. sp. and M. baoanensis n. sp. differ from other similar species in the length and morphology of the penis stylet.  The penis stylet of M. zhujiangensis n. sp. is C-shaped and its distal opening has a beveled edge. The penis stylet of M. baoanensis n. sp. is J-shaped and the distal region is thicker than other parts of the penis stylet. Molecular phylogenetic analysis supports the establishment of the new species.

Three new species of freshwater Macrostomum (Platyhelminthes, Macrostomida) from southern China.

Macrostomum is a diverse genus of turbellarians with more than 180 species described from around the world. However, the Macrostomum fauna in China is poorly known. In this study, three new species of freshwater Macrostomum were described from southern China based on morphology of the penis stylet, an important character for species identification in this genus. In M. heyuanensis n. sp., the penis stylet bends 108° leftwards at its 1/2 length then backwards besides the distal opening, and the terminal region is thicker than other parts of penis stylet. In M. dongyuanensis n. sp., the penis stylet is J-shaped, with the opening at the tail end. In M. bicaudatum n. sp., the penis stylet is C-shaped, with the upper margin of the distal end longer but slimmer than the lower margin. In addition, molecular phylogenetic analyses were conducted to aid the classification of the novel species. Finally, their habitat and taxonomic status are compared and discussed.

The complete mitochondrial genome of Hydra vulgaris (Hydroida: Hydridae).

The complete mitochondrial genome of Hydra vulgaris (Hydroida: Hydridae) is composed of two linear DNA molecules. The mitochondrial DNA (mtDNA) molecule 1 is 8010 bp long and contains six protein-coding genes, large subunit rRNA, methionine and tryptophan tRNAs, two pseudogenes consisting respectively of a partial copy of COI, and terminal sequences at two ends of the linear mtDNA, while the mtDNA molecule 2 is 7576 bp long and contains seven protein-coding genes, small subunit rRNA, methionine tRNA, a pseudogene consisting of a partial copy of COI and terminal sequences at two ends of the linear mtDNA. COI gene begins with GTG as start codon, whereas other 12 protein-coding genes start with a typical ATG initiation codon. In addition, all protein-coding genes are terminated with TAA as stop codon.

The complete mitochondrial genome of Chinese green hydra, Hydra sinensis (Hydroida: Hydridae).

The complete mitochondrial genome of Chinese green hydra, Hydra sinensis (Hydroida: Hydridae) is a linear molecule of 16,189 bp in length, containing 13 protein-coding genes, small and large subunit ribosomal RNAs, methionine and tryptophan transfer RNAs, a pseudogene consisting of a partial copy of COI and terminal sequences at two ends of the linear mitochondrial DNA. The A + T content of the overall base composition of H-strand is 77.2% (T: 41.7%; C: 10.9%; A: 35.5%; and G: 11.9%). COI and ND1 genes begin with GTG as start codon, while other 11 protein-coding genes start with a typical ATG initiation codon. COII, ATP8, ATP6, COIII, ND5, ND6, ND3, ND1, ND4 and COI genes are terminated with TAA as stop codon, ND4L ends with TAG, ND2 ends with TA and Cyt b ends with T.

Two new species of Gieysztoria (Platyhelminthes, Rhabdocoela, Dalyelliidae) from a freshwater artificial lake in Shenzhen, China.

Two new species of the "Aequales" of genus Gieysztoria were collected and described from an artificial lake on the Shenzhen University campus. Gieysztoria bimaculata n. sp., is distinguished based on two groups clavate pigmentations dorsally between the pharynx and intestine, and has a sclerotic stylet comprising a proximal girdle with 40-46 distal dagger-shape spines, thus has the maximum number of spines within "Aequales" group. Gieysztoria guangdongensis n. sp. has a sclerotic stylet with a proximal girdle and 18 distal blade-shaped spines. Comparison with similar species based mainly on stylet morphology suggests that Gieysztoria bimaculata n. sp. and Gieysztoria guangdongensis n. sp. are apparently different from the known species of Gieysztoria in this moment. In addition, the stability of the amount of distal spines of "Aequales" species is briefly discussed.

A new species of hydra (Cnidaria: Hydrozoa: Hydridae) and molecular phylogenetic analysis of six congeners from China.

A new species of genus Hydra (Cnidaria: Hydrozoa: Hydridae), Hydra shenzhensis sp. nov. from Guangdong Province, China, is described and illustrated. Most polyps have five tentacles. Column length reaches 11 mm when relaxed. Buds do not acquire tentacles synchronously. Stenotele is broad and pyriform in shape, 1.2 times as long as its width. Holotrichous isorhiza is asymmetrical and slender (more than 2.7 times as long as its width), with transverse and slanting coils. Atrichous isorhiza is long, resembling a melon-seed in shape. Desmoneme is asymmetrically pyriform in shape. The new species, belonging to the vulgaris group, is dioecious; sexual reproduction was found to occur mostly during November and December under conditions of dense culture or food shortage. Two to thirteen testes, cone-like shape with papilla, formed beneath the tentacles. One to three ovaries, with an egg cup, milky white in color, formed on body column. Ninety percent of individuals developed only one ovum. On a mother polyp, a fertilized ovum developed an embryonic theca covering its surface. The embryotheca is brown, with a spine-like structure, covering a layer of transparent, membrane-like material. For phylogenetic analysis, the mitochondrial cytochrome oxidase subunit I gene (COI) of six hydra species collected from China was amplified by polymerase chain reaction (PCR) and sequenced. Morphological characters in combination with molecular evidence support the hydra described here as a new species.