taxonID	type	description	language	source
03E60416FC30FFF1FE25E0FCFE5AFCD3.taxon	description	(Figures 1, 2) Material examined Infesting Metaplax sheni Gordon, 1931 (Figure 1), Qiongshan, Hainan Province, 20 ◦ 00 ′ N, 110 ◦ 30 ′ E, 7 June 1958, coll. Ruiyu Liu, holotype female (CIEG 580601), allotype male (CIEG 580602). Description of holotype Length (excluding uropods) 4.68 mm, maximum width across pereomere 4, 2.96 mm, head length 1.30 mm, head width 1.32 mm, pereon length 2.13 mm, pleon length 1.25 mm, sinistral distortion 40 ◦. Pereomeres distinct, but separation of pleomeres obscure. No pigmentation (Figure 2 A, B). Head expanded and rounded anteriorly, tapered anteriorly, with well-developed frontal lamina, extending anterolaterally. Eyes absent (Figure 2 A). Antenna of three articles, terminal one setose, antennule lacking (Figure 2 C). Maxilliped bearing stout, triangular non-articulating palp extending prominently forward, lacking setae; plectron short and sharply tapered (Figure 2 D). Barbula (Figure 2 E) with two prominent pointed falcate lateral projections on each side, outer one distinctly larger than inner; large tubercle medial to inner falcate projection and broad shorter tubercle medial to those. Pereon broadest across pereomere 4, gradually tapering anteriorly and posteriorly. Coxal plates absent. Pereomeres 3 – 5 with small mid-dorsal projections, pereomere 6 with prominent mid-dorsal projection, pereomere 7 recessed under pereomere 6, lacking projection. Dorsolateral bosses on pereomeres 1 – 4, and tergal projections only on left side of pereomeres 2 – 4 (Figure 2 A). Oostegites completely enclosing highly vaulted brood pouch (Figure 2 B). First oostegite (Figure 2 F, G) with ovate anterior segment and elongate subquadrate posterior segment, anterior segment smoothly rounded anteriorly, with slightly digitate internal ridge bearing five short lobes of various widths, posterior segment expanded at mid-length of lateral margin, tapering to rounded posterior tip. Last pair of oostegites smooth, lacking tubercles. Pereopods subequal, with all articles distinct and each article of nearly same size on all pereopods; all dactyli small and blunt (Figure 2 H, I). Pleomere 1 distinct with prominent narrow triangular mid-dorsal projection, pleomeres 2 – 5 apparently fused into one piece without any projections. Five pairs of biramous pleopods and lateral plates. Lateral plates, exopodites and endopodites of similar size and structure, with surfaces tuberculate and margins highly digitate (Figure 2 J). Uniramous uropods similar to structure of pleopods and lateral plates but shorter than lateral plates of pleomere 5. Description of allotype male Length 2.31 mm, maximal width across pleon 3, 0.46 mm, head length 0.16 mm, head width 0.25 mm, pleonal length 0.51 mm. All body segments distinct (Figure 2 K, L). Head semicircular, eyes lacking (Figure 2 K). Antenna of three articles, distal ones setose; antennule of five articles, extending beyond the margin of head (Figure 2 M). Pereomeres near subequal in width, with truncate margins. All pereomeres with prominent mid-ventral tubercles (Figure 2 L). Pereopods subequal in size, all articles distinct (Figure 2 N, O) Pleon of six pleomeres, first three with mid-ventral tubercles (Figure 2 L). Five pairs of uniramous tuberculiform pleopods, progressively smaller posteriorly. Pleomere 6 bearing uniramous lobes similar in structure and placement to pleopods (Figure 2 L). Etymology The specific name sheni is selected to honour Prof. Jia-rui Shen (1902 – 75), for his contributions to the research of Crustacea in China. It is also the species name of the host crab. Distribution and hosts Hainan province, China, infesting Metaplax sheni Gordon, 1931. Remarks The lack of antennules on the holotype may not be a species character but rather specific to this specimen. Lack of antennules, or even both antennae and antennules, has been reported in other bopyrids (e. g. Markham 2010: 168) but has never been used to distinguish species within the genus Megacepon. This species is most similar to Megacepon aff. goetici sensu Bourdon and Stock (1979, not M. goetici sensu stricto, see below) as well as to Megacepon disparatum sp. nov., described below. All three of these taxa have males with short pleotelson anterolateral projections and females with two long falcate projections on the lateral margins of the barbula. Megacepon sheni sp. nov. can be distinguished from M. aff. goetici by absence of medial boss on pereomere 5 of the female (present in M. aff. goetici), differently shaped oostegite 1 (inner mediolateral projection of anterior segment not tapered in M. sheni, digitations on ridge much smaller in M. sheni), and male with only three mid-ventral pleonal tubercles (M. aff. goetici with five tubercles). This new species can be distinguished from M. disparatum by the shape of the medial boss on pereomere 6 of the female (unilobed in M. sheni, bilobed in M. disparatum), oostegite 1 differently shaped (mediolateral projection of posterior segment projected in M. sheni, not projected in M. disparatum; nearly right angled notch near distal end of posterior segment in M. disparatum, lacking in M. sheni).	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	description	(Figures 3, 4) Material examined Infesting Metaplax sp. (Figure 3), Xinying coast, Hainan Province, 19 ◦ 53 ′ N, 109 ◦ 30 ′ E, 22 May 1955, coll. Yongliang Wang, holotype female (CIEG 550501), allotype male (CIEG 550502). Infesting Metaplax longipes Stimpson, 1858, Zhejiang, Qingjiang, Stn. 2, 29 ◦ 28 ′ N, 119 ◦ 50 ′ E, 20 September 1979, coll. unknown, paratype immature female (CIEG 790901) and mature male (CIEG 790902). Description of holotype Length (including uropods) 9.72 mm, maximal width across pereomere 4, 5.42 mm, head length 1.85 mm, head width 2.05 mm, pereon length 3.87 mm, pleon and uropodal length 4.00 mm, dextral distortion 35 ◦. Pereomeres distinct, but pleomeres incompletely fused. No pigmentation (Figure 4 A, B). Head broad anteriorly, somewhat tapered posteriorly, with narrow frontal lamina, extending around sides. Eyes lacking (Figure 4 A). Antenna of three articles, antennule of four articles, terminal articles of each setose (Figure 4 C). Maxilliped with straight, non-articulated, non-setose tapered palp and short plectron (Figure 4 D). Barbula with two long falcate lateral projections on each side, outer projection slightly longer than inner one, short triangular lobe medial to lateral projections (Figure 4 E). Pereon distinctly segmented, broadest across pereomere 4, coxal plates absent. Dorsolateral bosses on pereomeres 1 – 6, last three bosses on left side fused. Small tergal projections only on first two pereomeres (Figure 4 A). Pereomere 5 with very small indistinct mid-dorsal projection, pereomere 6 with bilobed anteriorly directed middorsal projection. Pereomere 7 recessed under pereomere 6 and lacking projection. Oostegites completely enclosing highly vaulted brood pouch (Figure 4 B). First oostegite (Figure 4 F, G) with ovate anterior segment and rectangular posterior segment; anterior segment smoothly rounded anteriorly with deeply angled indentation posterolaterally enclosing pereopod; digitate internal ridge with single long slender projection laterally and row of eight much smaller slender projections along margin, posterior segment with straight lateral and medial margins, posterolateral margin deeply notched and posteromedial region tapering to rounded tip. Last pair of oostegites with surface tubercles. Pereopods subequal (Figure 4 H, I). Pleomeres fused dorsally and segmented ventrally, segment 1 bearing prominent trifid mid-dorsal triangular projection, other pleomeres lacking projections. Five pairs of biramous pleopods and lateral plates. Digitate lateral plates shorter than exopodites, but longer than endopodites. (Figure 4 A, B). Uniramous uropods similar to pleopods and lateral plates and longer than either pleopods or total pleon length. Description of allotype male Length 2.27 mm, maximal width across pereomere 3, 0.64 mm, head length 0.13 mm, head width 0.36 mm. All body segments distinct (Figure 4 J, K). Head rectangular, eyes lacking (Figure 4 J). Antenna of three articles, without setae; antennule of six articles, extending beyond margins of head (Figure 4 L). Pereomere widths subequal, with truncate margins. Pereomeres 2 – 7 with prominent mid-ventral tubercles (Figure 4 K). Pereopods subequal, smaller posterior (Figure 4 M, N). Pleon of six pleomeres, first four pleomeres with mid-ventral tubercles (Figure 4 K), first five with tuberculiform pleopods, sixth pleomere produced into two symmetrical posterolateral projections, uropods lacking (Figure 4 K). Etymology The Latin adjective disparatum is selected to reflect the holotype’s possession of bilobate and trifid mid-dorsal projections on pereomere 6 and pleomere 1, respectively. Distribution and hosts Hainan Province, China, on Metaplax sp.; Zhejiang Province on Metaplax longipes Stimpson, 1858. Remarks This species is most similar to Megacepon aff. goetici sensu Bourdon and Stock (1979, not M. goetici sensu stricto, see below) as well as to M. sheni sp. nov., described above (see Remarks for M. sheni for similarities and difference between M. disparatum and M. sheni). Megacepon disparatum sp. nov. can be distinguished from M. aff. goetici by lack of a medial boss on pereomere 5 of the female (present in M. aff. goetici), differently shaped oostegite 1 (lateral margins nearly parallel in M. disparatum, not parallel in M. aff. goetici, nearly right-angled notch near distal end of posterior segment in M. disparatum, lacking in M. aff. goetici), and male with only four midventral pleonal tubercles (M. aff. goetici with five tubercles). An immature female (Figure 4 O) was also collected with a mature male that matches the allotype in all aspects. This female shows segmentation on the pleon that is lacking in the adult, and has only slightly developed medial projections on pereomeres 5, 6 and pleomere 2 (Figure 4 P). List of species and records of Megacepon George, 1947	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Muradium tetragonum (Fabricius, 1798) (Sesarmidae). Locality. Madras, India. Remarks. This description is incomplete, with most characters provided being sufficient only to identify as a bopyrid. The illustrations are very stylized and hard to interpret as indicated by Markham (2010). However, Shiino (1958) provided a clearer description of the species (see immediately below). Although George’s paper is often cited as “ 1946, ” it was published in 1947 (as per printed notice in bound volumes of the journal).	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Chiromantes dehaani (H. Milne Edwards, 1853) (Sesarmidae). Locality. Okayama, Japan. Remarks. Shiino’s (1958) record for this species may well represent Megacepon choprai sensu stricto based on the shape of the mediodorsal bosses and the raised nature of the dorsal ridges (lacking produced median bosses) on the female’s pereomeres. Unfortunately, neither Shiino nor George had a male specimen.	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Episesarma mederi (H. Milne Edwards, 1853) (Sesarmidae). Locality. Thailand. Remarks. The females reported by Markham (1980) do not appear to be conspecific with M. choprai, because they have strong mediodorsal bosses on pleomeres 1 – 6 (in contrast to the more generally raised dorsal pereomeres without medial bosses on M. choprai). Additionally, the male reported by Markham (1980) has a differently shaped head (more rectangular in shape with pointed mediolateral extensions) than otherwise reported for species of Megacepon and also a differently shaped pleotelson with moderately projected and stout posterolateral lobes. It may be that Markham’s (1980) record represents an undescribed species of Megacepon, but in the absence of males and topotypic material of M. choprai sensu stricto, it would be inadvisable to describe it at this time.	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Perisesarma maipoense (Soh, 1978) (Sesarmidae). Locality. Hong Kong. Remarks. Markham (1990) did not illustrate these specimens and mentioned only some small differences between them and his earlier material (Markham, 1980). We have no reason to think that this record is of a different taxon than that of Markham (1980), but it is very likely both records represent something other than M. choprai sensu stricto.	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Perasesarma erythodactyla (Hess, 1865) (Sesarmidae). Locality. Queensland, Australia. Remarks. This record may also not represent M. choprai sensu stricto, although there are, as noted by Markham (2010), similarities between the shapes of the first oostegites, they are not identical. The general body shape of this female is different from that of either M. choprai sensu stricto or sensu Markham (1980, 1990) and there are fewer mediodorsal bosses than in the material of Markham (1980, 1990) but more than on M. choprai sensu stricto. Unfortunately, once again, no male was present. In the absence of a male, and with only a single female, it is not possible to determine if this record is representative of an undescribed species.	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Gaetice depressus (De Haan, 1835) (Varunidae). Locality. Seto, Japan. Remarks. Shiino (1958) emended the species name to “ goeticii ” but the original spelling must be maintained. While Shiino (1934) provided excellent illustrations and descriptions of many of the salient features of both males and females, he did not illustrate or described the female’s oostegite I or barbula.	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Gaetice depressus (De Haan, 1835) (Varunidae). Locality. Ryûkyû, Japan. Remarks. The two records from Shiino (1939, see also immediately following) are especially problematic. If we accept the level of variability in the males reported by Shiino (1934, long distolateral pleotelson lobes, no medioventral tubercles) and Shiino (1939, nearly absent distolateral pleotelson lobes, first two pleomeres only with medioventral tubercles), then we encompass nearly all the range of variation seen in males in the genus Megacepon. Either there is more than one species parasitizing Gaetice depressus in Japan, or the males are highly polymorphic, which would make all purported species-specific characters of Megacepon males suspect. At present the females of M. goetici sensu lato do not show any corresponding degree of variation.	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Macrophthalmus japonicus (De Haan, 1835) (Ocypodoidea: Macrophthalamidae). Locality. Kyûsyû, Japan. Remarks. The record from a Macrophthalmus host is perhaps an aberrant occurrence of the parasite on this host because of settling of the larva on the wrong host species, which may happen in bopyrids (see Boyko, 2006). No other records of Megacepon species are known to infest hosts not in the Grapsoidea.	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Gaetice depressus (De Haan, 1835) (Varunidae). Locality. Mie Prefecture, Japan. Remarks. Shiino (1958) figured and discussed only the two male pleotelsons, which are much like that reported from Gaetice hosts by Shiino (1939), bearing short mediolateral projections, but with even more variability in the number of medioventral tubercles.	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Gaetice depressus (De Haan, 1835) (Varunidae). Locality. Hong Kong. Remarks. This immature female presents strong mediodorsal bosses on pereomeres 5 and 6, which is unlike that seen on M. goetici sensu stricto. Comparison of Markham’s (1982) record with the description of M. pleopodatopus shows clearly that they are conspecific (identical body shape, shape of oostegite 1, barbula shape).	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Metopograpsus oceanicus (Hombron and Jacquinot, 1846) (Grapsidae). Locality. 55 m, Sumbawa, Indonesia. Remarks. This taxon is probably not conspecific with M. goetici Shiino (1934). The female body shape, presence of mediodorsal bosses on pereomeres 5 and 6, and shape of male pleotelson are all quite different. Based on the shape of the barbula and oostegite 1, it is not conspecific with M. pleopodatopus (or any of the other species, including the two new ones described herein). However, the oostegite 1 and barbula of M. goetici sensu stricto have never been described or illustrated, so this probable new species from Indonesia should not be described until M. goetici is fully described for comparative purposes.	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Chiromantes dehaani (H. Milne Edwards, 1853) (Sesarmidae). Locality. Kuei-Chi, China. Remarks. At best, this is a species inquirendum described by Pearse (1930) from only a male specimen. It appears most similar to M. goetici and M. pleopodatopus and could represent either species. Collection of Megacepon material from topotypic hosts is needed to resolve the question of its identity.	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
03E60416FC35FFFAFDC0E123FD5EFDA8.taxon	biology_ecology	Host. Varuna litterata (Fabricius, 1798) (Varunidae). Locality. Sumba, Indonesia. Remarks. Although Bourdon (1981) questionably placed this species in the genus, it is either a good species of Megacepon or a junior synonym of M. goetici. It is not conspecific with any of the other species in the genus, and not with M. aff. goetici sensu Bourdon and Stock (1979). A full description of M. goetici, including oostegite 1 and barbula shape is required to decide the status of M. pleopodatopus. Megacepon sheni sp. nov. Sex known. Female and male. Host. Metaplax sheni Gordon, 1931 (Varunidae). Locality. Hainan Province, China. Remarks. See above under the species description. Megacepon disparatum sp. nov. Sex known. Female and male. Host. Metaplax longipes Stimpson, 1858 (Varunidae). Locality. Hainan Province, China. Remarks. See above under the species description.	en	An, Jianmei, Boyko, Christopher B., Li, Xinzheng (2011): Two new species of the genus Megacepon George, 1947 (Crustacea: Isopoda: Bopyridae) infesting Varunidae (Crustacea: Brachyura: Grapsoidea) from China. Journal of Natural History 46 (3 - 4): 131-143, DOI: 10.1080/00222933.2011.626128, URL: http://dx.doi.org/10.1080/00222933.2011.626128
