The systematics of land crabs of the genus Gecarcoidea and recognition of a pseudocryptic species, G. humei, from the eastern Indian Ocean (Crustacea : Decapoda : Gecarcinidae)

2017 ◽  
Vol 31 (4) ◽  
pp. 406 ◽  
Author(s):  
Joelle C. Y. Lai ◽  
Hsi-Te Shih ◽  
Peter K. L. Ng

The gecarcinid genus Gecarcoidea H. Milne Edwards, 1837 is currently represented by two species from the Indo-West Pacific – the widely distributed purple land crab, G. lalandii H. Milne Edwards, 1837, and the red crab endemic to Christmas Island, G. natalis (Pocock, 1889). One species, G. humei (Wood-Mason, 1874), described from the Nicobar Islands, has had a confused taxonomic history, but was treated as a junior synonym of G. lalandii by Türkay (1974) in his revision of the family. In this study, using molecular as well as morphological characters, we show that G. humei is a valid species. Gecarcoidea lalandii and G. humei have distinct non-overlapping distributions throughout much of their range, with G. lalandii occurring in most of South-east Asia and the West Pacific, while G. humei is known only from the eastern Indian Ocean. On Christmas Island, in the eastern Indian Ocean, however, all three species are present. As a result, Christmas Island is the only locality where all extant species of Gecarcoidea are found. The three species can also be separated by differences in live colours and patterns, as well as proportions of the carapace, male abdomen, ambulatory legs and third maxillipeds, and details of the orbits and male first gonopods.

Zootaxa ◽  
2013 ◽  
Vol 3609 (1) ◽  
pp. 1-25 ◽  
Author(s):  
PETER J.F. DAVIE ◽  
PETER K.L. NG

The identity of Chiromantes obtusifrons (Dana, 1851), previously considered widespread in the tropical West Pacific re-gion to the eastern Indian Ocean, is revised and found to be a species-complex. Chiromantes obtusifrons is now considered endemic to the Hawaiian Is., and four new species are described from Guam, Taiwan and Christmas Island. Two species live sympatrically in Taiwan. Species separation is based on carapace and frontal shape and granulation, leg proportions, abdominal somite proportions, and distinctive live colouration.


1997 ◽  
Vol 71 (6) ◽  
pp. 1109-1124 ◽  
Author(s):  
Li Guo-Qing ◽  
Mark V. H. Wilson ◽  
Lance Grande

Review of recently collected material of Eohiodon from North America suggests that there are two valid species, E. rosei (Hussakof) and E. woodroffi Wilson. Eohiodon falcatus Grande is identical to E. woodruffi in known skeletal features and nearly all meristic features and is treated as a junior synonym of the latter. The fossil genus Eohiodon Cavender differs from Hiodon Lesueur, which is known from both fossil and extant species, in numerous meristic and osteological features. The caudal skeleton in Eohiodon is nearly identical to that in Hiodon.The traditionally accepted Notopteroidei, containing Lycopteridae, Hiodontidae, and Notopteridae, is a polypheletic group. The Asian fossil family Lycopteridae is not more closely related to Hiodontidae than it is to other taxa in the Osteoglossomorpha, but is sister to all other Osteoglossomorpha. The Hiodontiformes sensu stricto, including only the family Hiodontidae, is the sister-group of the Osteoglossiformes. This family is not more closely related to notopterids than to other taxa in Osteoglossiformes. The Notopteridae are most closely related to the Mormyroidea; together they and the fossil family Ostariostomidae constitute the sister-group of the Osteoglossoidei.Fossil records of Hiodontiformes sensu stricto and Notopteroidei indicate a widespread pre-Neogene biogeographic range of these freshwater teleosts, suggesting that extinction must have been involved in the Cenozoic evolution of these two osteoglossomorph sublineages.


Crustaceana ◽  
2018 ◽  
Vol 91 (12) ◽  
pp. 1495-1504 ◽  
Author(s):  
Rajan Kumar ◽  
Shikha Rahangdale ◽  
Subal Kumar Roul

Abstract Albuneid crabs are specialized and active sand-burrowing organisms. Despite their substantial diversity, their ability to avoid fishing gear leads to “under collection” and a discontinuous record of distribution. The present study documents the first distributional record of Albunea occulta Boyko, 2002 from the Bay of Bengal, eastern Indian Ocean. Albunea thurstoni Henderson, 1893 is also recorded for the first time from the area, i.e., from the Gulf of Mannar, southwestern Bay of Bengal. This study further reports variation in morphological characters, especially in the carapace grooves (CG) from previous records and across specimens from different regions. Morphometric characters were found useful in species discrimination, which is explained as well.


2021 ◽  
Vol 750 ◽  
pp. 52-69
Author(s):  
Man-Kwan Wong ◽  
Mao-Ying Lee ◽  
Wei-Jen Chen

With six valid species, Luciobrotula is a small genus of the family Ophidiidae, commonly known as cusk-eels. They are benthopelagic fishes occurring at depths ranging from 115–2300 m in the Atlantic, Indian, and Pacific Oceans. Among them, Luciobrotula bartschi is the only known species in the West Pacific. Three specimens of Luciobrotula were collected from the Philippine Sea, Bismarck Sea, and Solomon Sea in the West Pacific during the AURORA, PAPUA NIUGINI, and MADEEP expeditions under the Tropical Deep-Sea Benthos program, and all of them were initially identified as L. bartschi. Subsequent examination with integrative taxonomy indicates that they belong to two distinct species, with the specimen collected from the Solomon Sea representing a new species, which is described here. In terms of morphology, Luciobrotula polylepis sp. nov. differs from its congeners by having a relatively longer lateral line (end of the lateral line below the 33rd dorsal-fin ray) and fewer vertebrae (abdominal vertebrae 13, total vertebrae 50). In the inferred COI gene tree, the two western Pacific species of Luciobrotula do not form a monophyletic group. The genetic K2P distance between the two species is 13.8% on average at the COI locus.


2020 ◽  
pp. 183-215
Author(s):  
Benny K. K. Chan ◽  
Kingsley J. H. Wong ◽  
Yu-Rong Cheng

Most of the diverse groups of crustaceans associated with scleractinian and fire corals form symbiotic relationship with their coral hosts. Coral-associated barnacles include species from the orders Acrothoracica and Thoracica. Most of the coral-associated barnacles belong to the family Pyrgomatidae in Thoracica. Within Pyrgomatidae, the subfamily Ceratoconchinae contains mostly extant species and is present from Florida through the Caribbean to Brazilian waters. The subfamily Megatrematinae has lower species diversity and has a cosmopolitan distribution (except the Eastern Pacific). The Pyrgomatinae are the most species-rich subfamily and distributed only in Indo-West Pacific waters. Host usage of pyrgomatinid barnacles varies spatially, probably related to coral host diversity. Copepods are the most common and most abundant coral-associated crustaceans, often associated with scleractinian, gorgonian, and alcyonacean corals. More than 90% of coral-associated copepods are endemic to the Indo-West Pacific. In contrast, only a few species (<10%) have been discovered from the Atlantic due to several historical perturbations reducing the diversity of their coral hosts. The communities of coral-associated copepods thus show dramatic differences between geographic regions, notably between the Indian, Pacific, and Atlantic Oceans. Brachyurans of the family Cryptochiridae (gall crabs) are obligate associates or parasites, of scleractinian coral hosts in tropical and subtropical seas, being a monophyletic group of only 52 species, from the intertidal to the deep sea (to 512 m) habitats with most (46) recorded in the seas of the tropical Indo-West Pacific and none being cosmopolitan. Atlantic species of Cryptochiridae, apparently not phylogenetically related, display less strict host specificity than their Indo-West Pacific counterparts. Current phylogenetic understandings of the group remain preliminary, while one consistent Indo-West Pacific clade reflects rapid species diversification during the last ~15 million years.


2012 ◽  
Vol 33 (2) ◽  
pp. 215-225 ◽  
Author(s):  
Massimo Delfino ◽  
Àngel H. Luján ◽  
Raül Carmona ◽  
David M. Alba

Testudo lunellensis Almera and Bofill, 1903 from the Middle Pleistocene of Cova de Gràcia (Park Güell, Barcelona, Spain) is a valid species belonging to the clade of the extant Testudo hermanni – a diagnostic feature being the narrowed vertebral scutes. Thanks to still unpublished material, T. lunellensis is diagnosed for the first time and its shell morphology described in detail. This species is uniquely characterized, among others, by tall peripheral bones and by a peculiar shape of the anterior lobe of the plastron, somewhat recalling the species referred to Testudo s.s. (the clade containing the extant species Testudo graeca, Testudo kleinmanni and Testudo marginata). Given that the purported valid species from Lunel-Viel (Middle Pleistocene, France) is still unnamed and undescribed, T. lunellensis from Cova de Gràcia is currently the stratigraphically youngest extinct Testudo species. The co-occurrence in T. lunellensis of characters typical of both T. hermanni and Testudo s.s. further testifies the phenotypic plasticity of tortoises and the mosaic distribution of morphological characters, which hinders a clear-cut assessment of the relationships of extant tortoises when based exclusively on morphology. Further analyses of the phylogeny of Testudo should consider fossil and extant taxa together, as well as both morphological and genetic characters.


2020 ◽  
Vol 100 (7) ◽  
pp. 1147-1153
Author(s):  
Subal Kumar Roul ◽  
N. S. Jeena ◽  
Shubhadeep Ghosh ◽  
Prathibha Rohit

AbstractCrenidens macracanthus was originally described in 1874 based on a single specimen collected from Chennai (Madras), south-east coast of India. In 1875, the species was synonymized with C. indicus without citing any valid reason. Since then, no taxonomic studies have been attempted for the genus Crenidens, except in 2013 the species was resurrected from synonymy and redescribed as a valid species based on the holotype and non-type specimen. In view of the fact that C. macracanthus is a poorly known species, it is redescribed based on examination of 30 additional specimens of 105.8–162.2 mm SL, collected from Puri, Odisha, north-east coast of India (Bay of Bengal) from 2017–2019, using morphological and molecular examinations. Our study provides a detailed morphological description, first colour photographs and phylogenetic analysis using COI barcodes of the species. The study has expanded the range in several morpho-meristic characters in comparison with the type and non-type specimens described earlier. The species in fresh condition can be easily distinguished from its two congeners (C. crenidens and C. indicus) by the yellowish tip of the lower caudal-fin lobe. Our study has also extended the distribution range of C. indicus (previously known only from the north-eastern Arabian Sea) to the eastern Indian Ocean, based on examination of a preserved specimen collected from Tuticorin, Tamil Nadu.


2020 ◽  
Vol 3 (3) ◽  
pp. 269-283
Author(s):  
WESLEY D. COLOMBO ◽  
EVGENY E. PERKOVSKY ◽  
CELSO O. AZEVEDO

The flat wasps, Bethylidae, are cosmopolitan and one of the most diverse families of Chrysidoidea. Bethylidae have 2,920 described extant species and almost 90 fossil species. The oldest geological record of the family is the Lower Cretaceous, from Lebanese and Spanish ambers and Transbaikalian rock fossils. Here we describe and illustrate one new fossil subfamily of Bethylidae: †Elektroepyrinae subfam. nov. represented by †Elektroepyris Perrichot & Nel from the lowermost Eocene Oise amber (France), which was cladistically assessed against all other eight subfamilies of Bethylidae. The new taxon is easily distinguished from other subfamilies by the forewing venation with the third abscissa of Cu present. Phylogenetic analyses support the monophyly of all subfamilies of Bethylidae, with a matrix with 69 morphological characters and 22 terminal taxa from where †Elektroepyrinae subfam. nov. emerged as independent lineage from all other subfamilies.


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