Two species of alpheid shrimp collected from a marine cave off Ie Island, Okinawa Islands, Ryukyu Islands, Japan, are reported. Caligoneus cavernicola n. gen., n. sp., is described on the basis of six specimens, including two ovigerous individuals. The new monotypic genus shares a number of features with Salmoneus Holthuis, 1955 and Triacanthoneus Anker, 2010; however, the dorsally elevated rostrum and the symmetrical pereopods 1 (= chelipeds) of “minor form” distinguish Caligoneus n. gen. from the latter two genera. Other potentially diagnostic characters between the new genus and the latter two genera are also discussed. The new taxon is clearly adapted to stygobiotic environments, with its reduced cornea and very slender elongate pereopods. In addition, two complete specimens of Salmoneus antricola Komai, Yamada & Yunokawa, 2015, collected in the same cave, supplement the original description of the species, which was based on a unique holotype with a damaged telson.
Keywords: Crustacea, Caligoneus cavernicola, Ie Island, stygobiotic, Triacanthoneus
Tomoyuki Komai and Yoshihisa Fujita. 2018. A New Genus and New Species of Alpheid Shrimp from A Marine Cave in the Ryukyu Islands, Japan, with Additional Record of Salmoneus antricolaKomai, Yamada & Yunokawa, 2015 (Crustacea: Decapoda: Caridea). Zootaxa. 4369(4); 575–586. DOI: 10.11646/zootaxa.4369.4.7
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رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا
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ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.
A new species of Takedactylus Naruse & Maenosono, 2012, and a new genus and species of Aphanodactylidae are described from Japan. Takedactylus compressus n. sp. is collected from Ogasawara Islands. This new species is distinct from the only congener, Takedactylus masatsunei, by the shapes of the carapace, third maxilliped and the ambulatory legs. Another new species, monotypic Lichtylus kaisha n. gen., n. sp., is distinct from all other aphanodactylid species, in generic level, in the shape and position of the palp of third maxilliped, relatively long and slender ambulatory legs, and a combination of other important characters, i.e. the contour of the carapace, the degree of gap between third maxillipeds, condition of the distoflexor corners of second to fifth ambulatory propodi, and relative length of ambulatory dactyli. The present study brings the number of aphanodactylid taxa to 7 genera and 15 species.
Keywords: Taxonomy, new genus, new species, Brachyura, crab, Aphanodactylidae, Japan
Tohru Naruse and Ryuta Yoshida. 2018. Two New Species of Aphanodactylidae (Crustacea: Decapoda: Brachyura) from the Ryukyu and Ogasawara Islands, Japan, with the Establishment of A New Genus. Tropical Zoology. DOI: 10.1080/03946975.2017.1395163
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رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا
تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا
ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.
Photographs (F, H–J) by Nathaniel Evans; photographs (E, G) by Gustav Paulay. in Evans, 2018. DOI: 10.7717/peerj.4260
Abstract
Portunoidea is a diverse lineage of ecologically and economically important marine crabs comprising 8 families and 14 subfamilies. Closely related portunid subfamilies Caphyrinae and Thalamitinae constitute some of this group’s greatest morphological and taxonomic diversity, and are the only known lineages to include symbiotic taxa. Emergence of symbiosis in decapods remains poorly studied and portunoid crabs provide an interesting, but often overlooked example. Yet the paucity of molecular phylogenetic data available for Portunoidea makes it challenging to investigate the evolution and systematics of the group. Phylogenetic analyses, though limited, suggest that many putative portunoid taxa are para- or polyphyletic. Here I augment existing molecular data—significantly increasing taxon sampling of Caphyrinae, Thalamitinae, and several disparate portunoid lineages—to investigate the phylogenetic origin of symbiosis within Portunoidea and reevaluate higher- and lower-level portunoid classifications. Phylogenetic analyses were carried out on sequences of H3, 28S rRNA, 16S rRNA, and CO1 for up to 168 portunoid taxa; this included, for the first time, molecular data from the genera Atoportunus, Brusinia, Caphyra, Coelocarcinus, Gonioinfradens, Raymanninus, and Thalamonyx. Results support the placement of all symbiotic taxa (Caphyra, Lissocarcinus, and two Thalamita) in a single clade derived within the thalamitine genus Thalamita. Caphyrina Paulson, 1875, nom. trans. is recognized here as a subtribe within the subfamily Thalamitinae. Results also support the following taxonomic actions: Cronius is reclassified as a thalamitine genus; Thalamonyx is reestablished as a valid genus; Goniosupradens is raised to the generic rank; and three new genera (Zygita gen. nov., Thranita gen. nov., and Trierarchus gen. nov.) are described to accommodate some Thalamita s.l. taxa rendered paraphyletic by Caphyrina. A new diagnosis of Thalamitinae is provided. Results also support a more conservative classification of Portunoidea comprising three instead of eight extant families: Geryonidae (Geryonidae + Ovalipidae; new diagnosis provided), Carcinidae (Carcinidae + Pirimelidae + Polybiidae + Thiidae + Coelocarcinus; new diagnosis provided) and Portunidae. Finally, 16s rRNA data suggests family Brusiniidae might not be a portunoid lineage.
Figure 1: Representatives of various Portunoidea taxa included in this study. (A) Brusinia profunda (USNM 277519; New Caledonia; preserved color); (B) Coelocarcinus foliatus (UF 40176; Guam); (C) Carupa tenuipes (UF 39918; Palau); (D) Libystes (UF 23926; Moorea Is.); (E) Lupocyclus cf. philippinensis (UF 41639; Luzon Is.); (F) Podophthalmus vigil (UF 24543; Moorea Is.); (G) Portunus (Cycloachelous) granulatus (UF 40021; Guam); (H) Portunus (Portunus) sanguinolentus (UF 24538; Moorea Is.). Photographs (A–C, G) by Nathaniel Evans; photographs (D–F, H) by Gustav Paulay.
This study constitutes the most comprehensive molecular phylogenetic analyses of Portunoidea to date, but highlights numerous areas where additional work is needed. Results support a more conservative classification of Portunoidea with three instead of eight extant families: Geryonidae (Geryonidae + Ovalipidae; new diagnosis provided), Carcinidae (Carcinidae + Pirimelidae + Polybiidae + Thiidae + Coelocarcinus; new diagnosis provided) and Portunidae. Limited molecular data also suggest that the family Brusiniidae may still be valid, but might not be a portunoid lineage. A major aim of this study was to investigate the molecular phylogenetic origin of symbiosis within Portunoidea by substantially increasing taxon sampling of the subfamilies Caphyrinae and Thalamitinae. Results support a shared ancestry of all symbiotic taxa (Caphyra, Lissocarcinus, and two Thalamita) derived within the thalamitine genus Thalamita. Consequently, Caphyrina Paulson, 1875, nom. trans., should be considered a subtribe within the subfamily Thalamitinae. Although the nature, degree, and phylogenetic pattern of symbiosis within Caphyrina needs further study, this clade is clearly dominated by symbiotic taxa and likely originated from a symbiotic ancestor. Results presented here also support the following taxonomic actions within Thalamitinae: Cronius is reclassified as a thalamitine rather than a portunine genus; Thalamonyx is reinstated as a valid genus; Goniosupradens is raised to the generic rank; and three new genera (Zygita gen. nov., Thranita gen. nov., and Trierarchus gen. nov.) are described to accommodate some Thalamita sensu lato taxa rendered paraphyletic by Caphyrina. A new diagnosis of Thalamitinae has also been provided.
Nathaniel Evans. 2018. Molecular Phylogenetics of Swimming Crabs (Portunoidea Rafinesque, 1815) supports A Revised Family-Level Classification and suggests A Single Derived Origin of Symbiotic Taxa. PeerJ. 6:e4260. DOI: 10.7717/peerj.4260
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شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا
رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا
تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا
ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.
In situ photographs of Pylopaguropsis mollymullerae sp. n. and its habitat at Bonaire diving site “Something Special”. A holotype male 2.4 mm, Bonaire (USNM 1291987) C three individuals of P. mollymullerae sp. n. (foreground, not collected) in den with “broad banded moray” Channomuraena vittata
A new secretive, yet brightly colored hermit crab species of the family Paguridae, Pylopaguropsis mollymullerae sp. n., is fully described based on specimens from the reefs of Bonaire, Lesser Antilles, southern Caribbean Sea. Populations of this new species were discovered and photographed in the Bonaire National Marine Park under a large coral ledge, at a depth of 13.7 m, living in crevices known by scuba divers to serve as den to a pair of “flaming reef lobsters” Enoplometopus antillensis, or a “broad banded moray” Channomuraenavittata. This new species is only the second species of Pylopaguropsis Alcock, 1905 known from the western Atlantic, the 20th named worldwide, and belongs in the teevana group of species of the genus. It is remarkably similar, and herein considered geminate, to the tropical eastern Pacific congener, P. teevana (Boone, 1932), the two being characterized and uniquely different from all other species of the genus, by the striking and deeply excavated, scoop-like ventral surface of the chela of the right cheliped. Minor differences separate this new species from P. teevana in the relative length of the antennal acicles (exceeding the corneas versus not exceeding the corneas in P. teevana); dorsal armature of the right chela (smooth or with scattered minute tubercles versus with numerous small tubercles in P. teevana); surface shape of the lateral face of the dactyl of right pereopod 3 (evenly convex versus flattened in P. teevana); and coloration (red bright red stripes versus brown stripes in P. teevana). The highly visible color pattern of bright red stripes on white background typical of decapods known to have cleaning symbioses with fish, dense setation on the flagella of the antennae, and preference for a crevicular habitat, combined with brief in situ nocturnal observations, suggests the possibility that P. mollymullerae sp. n. engages in “cleaner” activities or functions as a “den commensal” with moray eels. The morphology and possible meaning of the observed behavior is discussed. A tabular summary of the distribution, habitat, and published information on all species of Pylopaguropsis is presented. Supplemental photographs and a video of live P. mollymullerae sp. n. are included.
Figure 6. In situ photographs of Pylopaguropsis mollymullerae sp. n. and its habitat at Bonaire diving site “Something Special”. A holotype male 2.4 mm, Bonaire (USNM 1291987) B paratype male 1.8 mm, Bonaire (USNM 1291989) C three individuals of P. mollymullerae sp. n. (foreground, not collected) in den with “broad banded moray” Channomuraena vittata D coral ledge habitat, with arrow indicating entrance to crevice where five specimens of P. mollymullerae sp. n. were collected E individual of P. mollymullerae sp. n. (expanded and enhanced in oval inset, not collected) on body surface of “broad banded moray” C. vittata, with frontal portion of brachyuran Achelous sebae visible on lower right.
Figure 6. In situ photographs of Pylopaguropsis mollymullerae sp. n. and its habitat at Bonaire diving site “Something Special”. A holotype male 2.4 mm, Bonaire (USNM 1291987) B paratype male 1.8 mm, Bonaire (USNM 1291989) C three individuals of P. mollymullerae sp. n. (foreground, not collected) in den with “broad banded moray” Channomuraena vittata D coral ledge habitat, with arrow indicating entrance to crevice where five specimens of P. mollymullerae sp. n. were collected E individual of P. mollymullerae sp. n. (expanded and enhanced in oval inset, not collected) on body surface of “broad banded moray” C. vittata, with frontal portion of brachyuran Achelous sebae visible on lower right.
Distribution: So far known only from the island of Bonaire, Lesser Antilles, southern Caribbean Sea; depth: 11.6–13.7 m.
Etymology: The name of this new species is given to acknowledge the efforts of the collector, photographer and environmentalist, Ms Ellen Muller, who when informed of the intended honor, preferred that the name of her granddaughter, Ms Molly Muller, be used, in hopes to inspire her to continue the tradition of protecting the amazing and fragile diversity of marine life in Bonaire.
Common name: “Candy Striped Hermit Crab”, in reference to the bright white and red striped color pattern that is similar to that of traditional candy cane.
Rafael Lemaitre. 2017. Discovery of A New Species of Hermit Crab of the Genus Pylopaguropsis Alcock, 1905 from the Caribbean: “Den Commensal” or “Cleaner”? (Crustacea, Anomura, Paguridae). ZooKeys. 646: 139-158. DOI: 10.3897/zookeys.646.11132
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شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا
رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا
تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا
ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.
ปูเขาหินปูนทุ่งหว้า || RAFFLES BULLETIN OF ZOOLOGY.65
Abstract
A new species of potamid crab of the genus Terrapotamon Ng, 1986, is described from karst forests in Satun, Peninsular Thailand. Terrapotamon thungwa n. sp. has very long ambulatory legs and superficially resembles T. longitarsus, the only other long-legged species in the genus. They can easily be distinguished by life colouration, carapace features, as well as structures of the epistome, male thoracic sternum, cheliped and male first gonopod.
Subfamily Potamiscinae Bott, 1970, sensu Yeo & Ng, 2004
Genus Terrapotamon Ng, 1986
Terrapotamon thungwa n. sp.
Fig. 1. Terrapotamon thungwa n. sp., colour in life from Satun, Thailand. A–C, holotype male (44.6 × 35.0 mm) (ZRC 2016.0595).
Fig. 8. Terrapotamon thungwa n. sp., observed in the cave at Ban Namtok Than Plio, Amphoe Thung Wa, Satun, Thailand. A, paratype male (41.1 × 33.3 mm) (PSUZC-CRU-0072).
Fig. 8. Terrapotamon thungwa n. sp., observed in the cave at Ban Namtok Than Plio, Amphoe Thung Wa, Satun, Thailand. B, C, paratype female (29.4 × 23.8 mm) (PSUZC-CRU-0073).
Fig. 9B, Terrapotamon thungwa n. sp., specimen observed in cave in Ban Namtok Than Plio, Amphoe Thung Wa, Satun, Thailand.
Etymology. The name is derived from the type locality at Amphoe Thung Wa. The name is used as a noun in apposition.
Remarks. The long ambulatory legs of T. thungwa n. sp. is a character shared only by one other species of Terrapotamon,T. longitarsus Lheknim & Ng, 2016, also from the Satun area in Peninsular Thailand. It is surprising to find two similar species occurring in the same area, but the differences between the two species are very marked and leave no doubt they are separate taxa. Terrapotamon thungwa can most easily be separated in its bright red overall coloration in life (Figs. 1, 8A) (purple in T. longitarsus; Fig. 6); ....
Habitat. All the specimens of Terrapotamon thungwa were obtained from the karst landscape of Satun. From the material collected, it would appear that the area and habitat where T. thungwa occurs overlaps with T. longitarsus. Both species were found inside and outside the caves as well as in the karst forest. In the dark zone inside the cave, adults of T. thungwa were observed climbing on the cave walls (Fig. 8B, C), with a small specimen observed in a pool on the cave floor (Fig. 9A, B). Up to five specimens have been observed on the cave floor. Adult males of both two species were observed in rock pools at the bottom of deep crevices in the karst forest, while a small specimen of T. longitarsus were seen at a sheltered rock pool near the cave entrance (Fig. 9C, D). The crabs use these collected pools to replenish their gill chambers.
Rueangrit Promdam, Pun Yeesin and Peter K. L. Ng. 2017. A Second New Species of Terrestrial Long-legged TerrapotamonNg, 1986 (Crustacea: Brachyura: Potamidae) from Karst Forests in Peninsular Thailand. RAFFLES BULLETIN OF ZOOLOGY.65; 404–415.
كيف تحصل على مدونة جاهزة بآلاف المواضيع والمشاركات من هنا
شاهد قناة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على اليوتيوب لمزيد من الشرح من هنا
رابط مدونة منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات في أي وقت حــــتى لو تم حذفها من هنا شاهد صفحة منتدى مدونات بلوجر جاهزة بألاف المواضيع والمشاركات على الفيس بوك لمزيد من الشرح من هنا
تعرف على ترتيب مواضيع منتدى مدونات بلوجر جاهزة بآلاف المواضيع والمشاركات (حتى لا تختلط عليك الامور) من هنا
ملاحظة هامة: كل عمليات تنزيل، رفع، وتعديل المواضيع الجاهزة تتم بطريقة آلية، ونعتذر عن اي موضوع مخالف او مخل بالحياء مرفوع بالمدونات الجاهزة بآلاف المواضيع والمشاركات، ولكم ان تقوموا بحذف هذه المواضيع والمشاركات والطريقة بسيطة وسهلة. ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــسلامـ.
The present monograph includes general systematic considerations on the family Epimeriidae, a revision of the genus Epimeria Costa in Hope, 1851 in the Southern Ocean, and a shorter account on putatively related eusiroid taxa occurring in Antarctic and sub-Antarctic seas. The former epimeriid genera Actinacanthus Stebbing, 1888 and Paramphithoe Bruzelius, 1859 are transferred to other families, respectively to the Acanthonotozomellidae Coleman & J.L. Barnard, 1991 and the herein re-established Paramphithoidae G.O. Sars, 1883, so that only Epimeria and Uschakoviella Gurjanova, 1955 are retained within the Epimeriidae Boeck, 1871. The genera Apherusa Walker, 1891 and Halirages Boeck, 1891, which are phylogenetically close to Paramphithoe, are also transferred to the Paramphithoidae. The validity of the suborder Senticaudata Lowry & Myers, 2013, which conflicts with traditional and recent concepts of Eusiroidea Stebbing, 1888, is questioned. Eight subgenera are recognized for Antarctic and sub-Antarctic species of the genus Epimeria: Drakepimeria subgen. nov., Epimeriella K.H. Barnard, 1930, Hoplepimeria subgen. nov., Laevepimeria subgen. nov., Metepimeria Schellenberg, 1931, Pseudepimeria Chevreux, 1912, Subepimeria Bellan-Santini, 1972 and Urepimeria subgen. nov. The type subgenus Epimeria, as currently defined, does not occur in the Southern Ocean. Drakepimeria species are superficially similar to the type species of the genus Epimeria: E. cornigera (Fabricius, 1779), but they are phylogenetically unrelated and substantial morphological differences are obvious at a finer level. Twenty-seven new Antarctic Epimeria species are described herein: Epimeria (Drakepimeria) acanthochelon subgen. et sp. nov., E. (D.) anguloce subgen. et sp. nov., E. (D.) colemani subgen. et sp. nov., E. (D.) corbariae subgen. et sp. nov., E. (D.) cyrano subgen. et sp. nov., E. (D.) havermansiana subgen. et sp. nov., E. (D.) leukhoplites subgen. et sp. nov., E. (D.)loerzae subgen. et sp. nov., E. (D.) pandora subgen. et sp. nov., E. (D.) pyrodrakon subgen. et sp. nov., E. (D.) robertiana subgen. et sp. nov., Epimeria (Epimeriella) atalanta sp. nov., Epimeria (Hoplepimeria) cyphorachis subgen. et sp. nov., E. (H.) gargantua subgen. et sp. nov., E. (H.)linseae subgen. et sp. nov., E. (H.) quasimodo subgen. et sp. nov., E. (H.) xesta subgen. et sp. nov., Epimeria (Laevepimeria) anodon subgen. et sp. nov., E. (L.) cinderella subgen. et sp. nov., Epimeria (Pseudepimeria) amoenitas sp. nov., E. (P.) callista sp. nov., E. (P.) debroyeri sp. nov., E. (P.) kharieis sp. nov., Epimeria (Subepimeria) adeliae sp. nov., E. (S.) iota sp. nov., E. (S.) teres sp. nov. and E. (S.)urvillei sp. nov. The type specimens of E. (D.) macrodonta Walker, 1906, E. (D.) similis Chevreux, 1912, E. (H.) georgiana Schellenberg, 1931 and E. (H.) inermis Walker, 1903 are re-described and illustrated. Besides the monographic treatment of Epimeriidae from the Southern Ocean, a brief overview and identification keys are given for their putative and potential relatives from the same ocean, i.e., the Antarctic and sub-Antarctic members of the following eusiroid families: Acanthonotozomellidae Coleman & J.L. Barnard, 1991, Dikwidae Coleman & J.L. Barnard, 1991, Stilipedidae Holmes, 1908 and Vicmusiidae Just, 1990. This overview revealed the existence of a new large and characteristic species of Alexandrella Chevreux, 1911, A. chione sp. nov. but also shows that the taxonomy of that genus remains poorly known and that several ‘variable widespread eurybathic species’ probably are species complexes. Furthermore, the genera Bathypanoploea Schellenberg, 1939 and Astyroides Birstein & Vinogradova, 1960 are considered to be junior synonyms of Alexandrella. Alexandrella mixta Nicholls, 1938 and A. pulchra Ren in Ren & Huang, 1991 are re-established herein, as valid species. It is pointed out that this insufficient taxonomic knowledge of Antarctic amphipods impedes ecological and biogeographical studies requiring precise identifications. Stacking photography was used for the first time to provide iconographic support in amphipod taxonomy, and proves to be a rapid and efficient illustration method for large tridimensionally geometric species. A combined morphological and molecular approach was used whenever possible for distinguishing Epimeria species, which were often very similar (albeit never truly cryptic) and sometimes exhibited allometric and individual variations. However in several cases, taxa were characterized by morphology only, whenever the specimens available for study were inappropriately fixed or when no sequences could be obtained. A large number of Epimeria species, formerly considered as eurybathic and widely distributed, proved to be complexes of species, with a narrower (overlapping or not) distribution. The distributional range of Antarctic Epimeria is very variable from species to species. Current knowledge indicates that some species from the Scotia Arc and the tip of the Antarctic Peninsula are narrow range endemics, sometimes confined to one island, archipelago, or ridge (South Georgia, South Orkney Islands, Elephant Island or Bruce Ridge); other species have a distribution encompassing a broader region, such as the eastern shelf of the Weddell Sea, or extending from the eastern shelf of the Weddell Sea to Adélie Coast. The most widely distributed species are E. (D.) colemani subgen. et sp. nov., E. (E.) macronyx (Walker, 1906), E. (H.) inermis Walker, 1903 and E. (L.) walkeri (K.H. Barnard, 1930), which have been recorded from the Antarctic Peninsula/South Shetland Islands area to the western Ross Sea. Since restricted distributions are common among Antarctic and sub-Antarctic Epimeria, additional new species might be expected in areas such as the Kerguelen Plateau, eastern Ross Sea, Amundsen Sea and the Bellingshausen Sea or isolated seamounts and ridges, where there are currently no Epimeria recorded. The limited distribution of many Epimeria species of the Southern Ocean is presumably related to the poor dispersal capacity in most species of the genus. Indeed with the exception of the pelagic and semi-pelagic species of the subgenus Epimeriella, they are heavy strictly benthic organisms without larval stages, and they have no exceptional level of eurybathy for Antarctic amphipods. Therefore, stretches deeper than 1000 m seem to be efficient geographical barriers for many Epimeria species, but other isolating factors (e.g., large stretches poor in epifauna) might also be at play. The existence of endemic shelf species with limited dispersal capacities in the Southern Ocean (like many Epimeria) suggests the existence of multiple ice-free shelf or upper slope refugia during the Pleistocene glaciations within the distributional and bathymetric range of these species. Genera with narrow range endemics like Epimeria would be excellent model taxa for locating hotspots of Antarctic endemism, and thus potentially play a role in proposing meaningful Marine Protected Areas (MPAs) in the Southern Ocean.
Cédric d'Udekem d'Acoz and Marie L. Verheye. 2017. Epimeria of the Southern Ocean with Notes on Their Relatives (Crustacea, Amphipoda, Eusiroidea). European Journal of Taxonomy. 359; 1–553. DOI: 10.5852/ejt.2017.359
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