Jibao Jiang

Four new earthworm species of the genus Amynthas Kinberg (Oligochaeta: Megascolecidae) from the island of Hainan and Guangdong Province, China

This paper describes four new species of morrisi-group earthworms from Hainan and Guangdong Provinces, China: Amynthas instabilis sp. nov, Amynthas dilatatus sp. nov, Amynthas infuscuatus sp. nov. and Amynthas qiongzhongensis sp. nov. All four species have two pairs of spermathecal pores in 5/6–6/7; male pores in XVIII, 0.33 circumference ventrally apart, each on the top of a slightly raised porophore, surrounded by several tiny genital papillae, in a pulvinate pad with three to six circular folds. Characters of the spermathecae, prostate glands and other anatomical features easily distinguish the new species from earthworms previously reported from the morrisi-group. http://zoobank.org/urn:lsid:zoobank.org:pub:545E9152-C826-44A2-949E-402434D8493D.

Molecular Phylogeny of Pheretimoid Earthworms (Haplotaxina: Megascolecidae) Based on Mitochondrial DNA in Hainan Island, China

In the Chinese Hainan Island, Amynthas and Metaphire are two dominated pheretimoid earthworm species belonging to the family Megascolecidae. They differ from earthworms in the adjacent regions in their morphology and at the molecular level, which could have occurred due to the unique geography of Hainan Island. Hainan Island is made of two tectonic parts linked to South China and Indochina blocks, respectively. In addition, there is an apparent complicated link between Hainan Island and mainland China because of the different plate movements and sea level changes. In order to understand the evolution of pheretimoid earthworms in Hainan Island, we first investigated the earthworm biodiversity here. Bayesian phylogenetic tree was then constructed from 3511 base pairs from five mitochondrial genes: COI, COII, 16S, 12S, and ND1. Their divergent time was finally traced based on the molecular clock of 2.0-2.4% substitutions/Ma. The results showed three species differentiations between Hainan and Guangdong earthworm species. According to the paleogeography of Asiatic regions (including Hainan Island itself), we hypothesized that the Hainan pheretimoid earthworms might originate from Southeast Asia, and then they dispersed to the south and finally arrived at South China and Hainan Island. Meanwhile, due to the geology movement of the adjacent plates, there was also the migration of earthworms among adjacent regions. Furthermore, we also considered that the relationship between genera Metaphire and Amynthas might be re-considered as one genus.

New Amynthas species (Oligochaeta: Megascolecidae) from south and central Hainan Island, China and estimates of evolutionary divergence among some corticis-group species

This paper describes four new species of earthworms from Hainan Island, China: Amynthas obsoletus sp. nov., Amynthas dorsualis sp. nov., Amynthas mirifius sp. nov. and Amynthas pulvinus sp. nov. Amynthas obsoletus is an athecate earthworm, has greyish or brownish pigment on the dorsum, and has two genital papillae beside each male pore, one medial and one anterior, three genital papillae arranged transversely in VIII, prostates in XVII–XX. Amynthas dorsualis, Amynthas mirifius and Amynthas pulvinus are all octothecate earthworms, and key to the corticis-group, but the spermathecal pores are located on the dorsum in Amynthas dorsualis. Amynthas dorsualis has dark grey and dark brown pigment on the dorsum, an annular clitellum in 1/10XIV–7/10XVI, and lacks genital markings. Amynthas mirifius and Amynthas pulvinus both have four pairs of spermathecal pores on the ventrum. Amynthas mirifius has four peanut-in-shell-shaped genital markings, which are rectangular with enlarged rounded ends, between the two male pores, while Amynthas pulvinus has a large glandular rounded rectangle-shaped genital marking on the ventral side of 17/18–18/19. DNA barcodes are provided for the last two new species collected in 2011, and have been submitted to NCBI to enable molecular species identification. http://www.zoobank.org/urn:lsid:zoobank.org:pub:27AD7191-5438-4F10-B177-5FCCA893A2EB

Four new species of genus Amynthas (Oligochaeta, Megascolecidae) from Hainan Island, China

Four new earthworm species of the genus Amynthas are described from Hainan Island, China. They are Amynthas endophilus sp. nov., Amynthas fluviatilis sp. nov., Amynthas fucatus sp. nov. and Amynthas apapillatus sp. nov. Amynthas apapillatus sp. nov. has three spermathecal pores in 6/7–8/9 while the other three new species have two pairs of spermathecal pores in 5/6–6/7. Their anatomical and morphological characteristics are compared to similar species from Hainan Island, China mainland and South-East Asia. Furthermore, COI and 16S gene sequences of these new species are submitted to NCBI. http://www.zoobank.org/urn:lsid:zoobank.org:pub:33B61DE5-BE64-47E9-B77C-D6234D25803B

Hainan earthworm community and the comparison with other East and Southeast Asia countries for geographic distribution and endemic rate

Abstract This paper presents an up-to-date list of the terrestrial earthworms of Hainan Island, which is the second largest island of China and separated by Qiongzhou Strait from the Leizhou Peninsula, Guangdong Province. Actually, 45 species are already known in this island, 60% of which is native species. Ten new species which were collected in the fieldwork in 2006 are also included in the list. Of these 45 species, 82% belongs to the family Megascolecidae, with the dominant genus Amynthas (70%). Some of the species also disperse in other regions of the Southeast Asia and China mainland, except 5 species only have a limited distribution. The endemism rate of Hainan (60%) is similar with that of China mainland (66%) and Taiwan (58%), but its endemism rate of Amynthas (77%) is much higher. All of these results maybe have some links with the geographical history of Hainan Island.

Phylogenetic evaluation of Amynthas earthworms from South China reveals the initial ancestral state of spermathecae

Our knowledge of the phylogeny of the earthworm genus Amynthas under the family Megascolecidae, which is comprised of a huge number of species, is very limited compared to the better-known and much smaller family Lumbricidae. In order to investigate the phylogenetic relationships among the species within the genus Amynthas, which is the largest genus of the Megascolecidae family, nuclear and mitochondrial DNA sequences of 77 species, including 76 in-group Amynthas species collected from South China and 1 out-group species, were analyzed. A 5402bp segments composed of whole nuclear 18S rDNA and the mitochondrial genes COI, COII, ND1, 12S, and 16S was assembled from 77 species. Maximum Likelihood and Bayesian analyses of the concatenated sequences were performed. The results revealed evolution of two geographically independent lineages, both showing the ancestral state of two pairs of spermatheca (Sp.p 7/8/9). We found the species groups described by Sims and Easton (1972) to be non-monophyletic, and the origin of the parthenogenetic species group to likely be a quadthecal ancestor. These results provide modest evidence in support of an Indochinese peninsula origin of the Chinese Amynthas species and divergence of the genus once it had spread to mainland China. The findings of this study are consistent with a divergence scenario that resulted in at least one branch spreading to the Southeast of China and another branch spreading to the Southwest of China, but further research is required to confirm this interpretation of the Amynthas phylogeny.

Four new earthworms of the genus Amynthas (Oligochaeta: Megascolecidae) from Mount Emei, Sichuan Province, China

ABSTRACT Four new species were collected from Mt. Emei, Sichuan Province, China. They are Amynthas leshanensis sp. nov., Amynthas gilvus sp. nov., Amynthas retortus sp. nov. and Amynthas orbicularis sp. nov. The first three species could be assigned to the Amynthas sieboldi group and the last species could be assigned to the Amynthas aeruginosus group according to the definition of Sims and Easton. A. leshanensis sp. nov. has the male pore porophore surrounded by a large irregular-shaped pad which extends from 17/18–½ XIX, and the intestinal caeca are complex. A. gilvus sp. nov. has each male pore on a slightly raised elliptical glandular flat-top pad, with a pointed extension lateral to each porophore. Amynthas retortus sp. nov. has a pair of small, round post-setal genital papillae medial to male porophores on XVII, spermathecal seminal chambers are twisted into zigzags and accessory glands are present on spermathecae and prostate gland areas. A. orbicularis sp. nov. has the spermathecal pores near dorso-lateral, complex intestinal caeca complex, three accessory glands with long ducts near the male pores, and the spermathecal seminal chambers are twisted into zigzags. The barcode data (partial sequence of mitochondrial cytochrome c oxidase subunit I) of each species has been submitted to the National Center of Biotechnology Information GenBank. http://zoobank.org/urn:lsid:zoobank.org:pub:5B82315E-5CF8-4048-87C4-B702021464B5

Two new species of earthworms belonging to the genus Amynthas (Oligochaeta: Megascolecidae) from Guangxi Province, China

Two new species of earthworms belonging to the genus Amynthas are described from Guangxi Province, China: Amynthas crassitubus sp. nov. and Amynthas stabilis sp. nov. from Shiwan Mountain Nature Reserve. The two species have three pairs of spermathecal pores in 6/7-8/9, and belong to the sieboldi-group. COI barcode sequences support their status as new species.

Three new earthworm species of the tokioensis -group in the genus Amynthas (Oligochaeta: Megascolecidae) from Guangxi Province, China

Three new species of the genus Amynthas are described from Guangxi Province, China. They are named A. dissimilis sp. nov., A. anteporus sp. nov. and A. marsupiformis sp. nov. All of them have two pairs of spermathecal pores in 6/7-7/8, and belong to the tokioensis-group. Their morphological characteristics are compared to similar species in tokioensis-group from China and other Asian countries. In addition, the mitochondrial COI and 12S-tRNA-Val-16S sequence of three new species were determined, then pairwise distances between species were calculated. Both morphological and molecular evidences could easily distinguish the new species from earthworms previously reported in the tokioensis-group.

Four new Amynthas and Metaphire earthworm species from nine provinces in southern China

Four new species belonging to genera Amyntha and Metaphire were discovered from an extensive area in southern China, covering the provinces Sichuan, Yunnan, Guizhou, Guangdong, Guangxi, Fujian, Hunan, Jiangxi and Anhui. The species are named Amynthas dispersus Sun Qiu, sp. nov., Amynthas shanghangensis Sun Qiu, sp. nov., Amynthas dentiformis Sun Jiang, sp. nov. and Metaphire sanmingensis Sun Jiang, sp. nov. The first two new species have four pairs of intersegmental spermathecal pores in 5/6-8/9. A. dispersus has elliptical and glandular male pore porophores raised on a low pad-like area surrounded by two to three shallow skin folds, the genital papillae are variable in the spermathecal pore and male pore regions, and prostate glands are vestigial or rudimentary. Amynthas shanghangensis has male porophores surrounded by three papillae, each prostate gland accompanied by an accessory gland, and the distal ½-⅓ of the spermathecal diverticulum dilated into a rod-shaped seminal chamber. Amynthas dentiformis has two pairs of spermathecal pores in 7/8-8/9, male pores always surrounded by two papillae, and small sacs on the dorsal and ventral margins of the intestinal caecae; the prostate gland occasionally has stalked accessory glands. M. sanmingensis is in the Metaphire houlleti-group, and has secondary male pores opening to copulatory pouches, rod-shaped spermathecal seminal chamber, as well as variable genital papillae in spermathecal and male pores regions. The GenBank accession numbers of DNA barcode data are attached under the description of each species.