ABSTRACT
A new species of Glossocephalus, G. aurantium sp. nov., is described based on two female specimens collected from the Monterey Canyon, California, eastern Pacific Ocean. It was found associated with an undescribed lobate ctenophore. Glossocephalus aurantium is readily distinguished from its congeners by the large crescent-shaped bulbous eye fields relative to the size of the head capsule. The pereopod morphology is most similar to G. rebecae, recently described from the same general region by Zeidler and Browne (2015), but that species is readily distinguished by it's relatively narrow crescent-shaped eye fields. Apart from it's prominent bulbous eye structures, G. aurantium is distinguished from G. milneedwardsi by the morphology of the gnathopods (not spoon-shaped). In addition, pereopods 5 and 6 are slender (not paddle-like) and the head capsule is relatively larger with a sharp rostrum (not rounded).
Subject(s)
Amphipoda , Female , Animals , Amphipoda/anatomy & histology , CaliforniaABSTRACT
An annotated checklist of the marine amphipods recorded from Indian waters is compiled from the available peer-reviewed literature. A total of 266 species belonging to 133 genera and 56 families are listed. The maximum numbers of species were recorded from the South Indian Ecoregion (177 species, 98 genera, 47 families), followed by the Western India Ecoregion (101 species, 72 genera, 36 families), the Eastern Indian Ecoregion (99 species, 65 genera, 35 families), the Northern Bay of Bengal Ecoregion (92 species, 53 genera, 29 families), the Maldives Ecoregion (32 species, 24 genera, 16 families), and the Andaman and Nicobar Islands Ecoregion (31 species, 22 genera, 18 families). Notes on the questionable identifications and records of some amphipods are also provided.
Subject(s)
Amphipoda , Humans , Animals , IndiaABSTRACT
Megalanceoloides remipes is a rare deep-sea species known from very few specimens. Until recently (Zeidler 2019) it was known only from the type, an incomplete female, and one other specimen, probably a juvenile female (Vinogradov 1964). Another specimen, an ovigerous female, described by Gasca Haddock (2016) and compared to the previous two, was later considered to be a new species, M. aequanime Gasca, 2017 (Gasca Browne 2017). More recently, Williams Bunkley-Williams (2019) proposed another new species, M. gascae, for the specimen described by Vinogradov (1964). Thus, a redescription of M. remipes is still required, especially in light of the two new species proposed by these authors. The recent discovery of several specimens of M. remipes, including both sexes, in the USNM (Zeidler 2019) has now made it possible to provide a detailed redescription of the species, together with the first description of males, enabling a better comparison with M. aequanime and M. gascae.
Subject(s)
Amphipoda , Gadiformes , Animals , Female , MaleABSTRACT
Lanceola loveni antarctica and L. sphaerica are rare deep-sea species known from very few specimens. Until recently (Zeidler 2019) L. loveni antarctica was known only from the types, seven specimens (727 mm), from the Indian Ocean Sector of the Antarctic (Vinogradov 1962). Similarly, L. sphaerica, originally described as a variety of L. clausi (Vinogradov, 1957), based on two damaged specimens, a female (8.0 mm) and a male (9 mm), from the Kurile-Kamchatka region of the NW Pacific, later elevated to full species status by Vinogradov (1970) upon the discovery of a well-preserved male (5 mm) from the same general region, was until then known only from these three specimens. The recent discovery of several specimens of both species in the USNM (Zeidler 2019) has now made it possible to provide a more detailed redescription of these rare species, including some new distribution records.
Subject(s)
Amphipoda , Animals , Antarctic Regions , Female , MaleABSTRACT
This is the first comprehensive taxonomic review of the family Brachyscelidae. The family is currently mono-generic following the review of Zeidler (2016). There are 17 nominal species referable to the genus Brachyscelus in the literature including two old references to species that most likely represent species of Brachyscelus. However, most are regarded junior synonyms of the two better known species B. crusculum Spence Bate, 1861 and B. globiceps (Claus, 1879). The taxonomic status of all nominal species was re-determined by the examination of extant type material or from the original literature reference if type material could not be found. In conclusion, five species of Brachyscelus are recognized as valid. Brachyscelus crusculum is the most common and widespread species and is most often recorded in the literature, but it is likely that some of these literature records are erroneous because other species have been confused with it in the past. The other species recognized are B. globiceps, B. macrocephalus Stephensen, 1925, B. rapacoides Stephensen, 1925 and B. rapax (Claus, 1871). Brachyscelus globiceps and B. macrocephalus are well established species and the validity of B. rapacoides was recently confirmed by Zeidler et al. (2018) but the validity of B. rapax is difficult to determine because type material could not be found and the original description by Claus (1871) and later figure (Claus 1887) are very inadequate. However, the species is tentatively recognized here based on several specimens which are most likely this species as according to Claus (1871, 1887). Brachyscelus is widely distributed in tropical and warm-temperate regions of the worlds oceans including the Mediterranean Sea. Species are preferentially associated with medusae and to a lesser extent with salps.
Subject(s)
Amphipoda , Heteroptera , Hydrozoa , AnimalsABSTRACT
New and additional records of hyperiidean amphipods of the infraorder Physosomata from the Antarctic Zone of the Southern Ocean, based on specimens in the USNM, are documented. They represent several range extensions for species previously recorded from the region as well as 14 new records with another three recorded from within a few degrees north of the Antarctic Zone. The following species represent new records for the Antarctic Zone: Lanceola loveni loveni, L. sphaerica, Megalanceoloides remipes, Microphasmoides vitjazi, Mimonecteola diomedeae, M. macronyx, Mimonectes diomedeae, M. loveni, Cheloscina antennula, Ctenoscina macropa, Scina curilensis, S. incerta, S. stebbingi and S. vosseleri. In addition, Lanceola felina, L. loveni grossipes and L. pacifica are recorded for the first time from the Southern Ocean, just 1°-3°N of the Antarctic Zone.
Subject(s)
Amphipoda , Animals , Antarctic Regions , Oceans and SeasABSTRACT
The hyperiidean amphipod Brachyscelus rapacoides Stephensen, 1925 is recorded from the scyphozoan jellyfish Rhopilema nomadica Galil, 1990, a new record of association for the genus Brachyscelus, as well as the first record of hyperiid infestation of a non-indigenous scyphozoan host. Because of some past confusion concerning the status of B. rapacoides and the closely related species B. rapax (Claus, 1871) a redescription of B. rapacoides and molecular analysis are provided in order to validate it as a species distinguished from B. rapax.
Subject(s)
Amphipoda , Scyphozoa , Animals , Mediterranean SeaABSTRACT
The generic name Euscelus was originally proposed by Schoenherr (1833: 205) for a genus of Leaf Rolling weevils (Insecta: Coleoptera: Attelabidae). It is a valid name, in current use, for a relatively large genus of weevils, widespread in northern South America and central America, including the West Indies and the Caribbean (e.g. Hamilton 2007; Legalov 2007). Euscelus Claus, 1879 was established as a monotypic genus of pelagic amphipod (Crustacea: Amphipoda: Hyperiidea: Parascelidae). It is a very rare genus, still monotypic, with the only species, E. robustus Claus, 1879, having been recorded only twice in the literature prior to my review of the families and genera of the superfamily Platysceloidea (Zeidler 2016); initially by Claus (1879), from the Indian Ocean (off Zanzibar), and secondly by Spandl (1927), from the North Atlantic Ocean (off the Azores). Both authors only recorded males. While examining the collections of the Zoological Museum, University of Copenhagen (Zeidler 2016) more specimens of this rare species were located amongst the collections of the Dana expeditions of 1928-1930 (Jespersen & Tåning 1934), thus enabling a more complete description of the species including that of females. It was recently brought to my attention that, according to the data base Interim Register of Marine and Nonmarine Genera (Rees 2016), Euscelus Claus, 1879 is a junior homonym of Euscelus Schoenherr, 1833. While researching this problem I discovered that Stebbing (1888) had also become aware of this homonymy and had suggested the replacement name Eusceliotes. Unfortunately, Stebbing (1888) only refers to the name in his index (pp. 1672, 1699) and hence subsequent authors were unaware of the above homonymy and Stebbing's replacement name, although it is listed by Neave (1939: 370). The purpose of this communication is to resolve the above homonymy by validating Stebbing's (1888) replacement name. This action is preferred to proposing yet another new name for Euscelus Claus, 1879, in order to avoid further confusion, because Stebbing's name, Eusceliotes, already exists in the literature (Stebbing 1888, Neave 1939).
Subject(s)
Amphipoda , Coleoptera , Animals , Atlantic Ocean , Azores , Caribbean Region , Central America , Female , Indian Ocean , Male , North America , South America , Tanzania , West IndiesABSTRACT
The systematics and phylogenetic relationships of the families and genera of the superfamily Platysceloidea are examined, following a thorough examination of the morphology of an example of the type species of each genus, or a substitute species if the true identity of the type species is in doubt. The mouthparts are described for each type species, often for the first time, providing additional characters for phylogenetic analysis. Genera are diagnosed using the taxonomic database program DELTA (Dalwitz et al. 1999). This database is also used for a phylogenetic analysis of the genera using PAUP (Swofford 2000). Proposed taxonomic changes resulting from this study are summarised as follows. The family Pronoidae is restricted to the monotypic genus Pronoe because it has some unique characters not found in any other platysceloidean. Paralycaea, previously in Pronoidae, has characters in common with Amphithyrus and Amphithyropsis gen. nov., a new genus proposed for Paralycaea platycephala Zeidler, 1998 (here re-determined a junior synonym of Tetrathyrus pulchellus Barnard, 1930), and together they form the proposed new family Amphithyridae fam. nov. Eupronoe and Parapronoe, also previously in Pronoidae, are similar in the morphology of the mouthparts, antennae and gnathopoda, and together form the proposed new family Eupronoidae fam. nov. The family Brachyscelidae is restricted to the genus Brachyscelus because Thamneus, previously included in Brachyscelidae, has a number of characters that differ considerably from any other genus of Hyperiidea and it is therefore placed in a family of its own, Thamneidae fam. nov. The status of the family Anapronoidae, for Anapronoe, is confirmed, as is the status of the family Tryphanidae for Tryphana. The family Lycaeidae is limited to Lycaea and Simorhynchotus. The family Oxycephalidae maybe polyphyletic but more work is required to resolve the systematic status of the eight genera currently recognised. Metalycaea globosa Stephensen, 1925, sometimes included in the Oxycephalidae, is confirmed to be a junior synonym of Lycaea serrata Claus, 1879. The family Platyscelidae is restricted to four genera, Platyscelus, Paratyphis, Hemityphis and Tetrathyrus; Amphithyrus having been removed to the new family Amphithyridae. The family Parascelidae is also restricted to four genera, Parascelus, Thyropus, Schizoscelus and Euscelus. Hemiscelus, previously included in this family, is regarded a junior synonym of Hemityphis. Keys are provided for families, genera and all currently known species. All records of associations with gelatinous zooplankton are also documented, providing additional data to help resolve the phylogeny and evolutionary origins of the Hyperiidae.
Subject(s)
Amphipoda/classification , Amphipoda/anatomy & histology , Amphipoda/growth & development , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Female , Male , Organ SizeABSTRACT
A new species of Glossocephalus, G. rebecae sp. nov., is described from deep-water in the Monterey Bay region of California, Eastern Pacific Ocean. It seems to be associated exclusively with the mesopelagic ctenophore Bathocyroe fosteri. This association has been observed from 541-830 m depth. It is readily distinguished from G. milneedwardsi Bovallius, 1887 by the shape of the eye fields. The retina is organised into a crescent-shaped organ, occupying about one-quarter of the back half of the head, with the crystalline cones projecting both anteriorly and laterally. An updated review of the genus is provided, taking into account the new species, together with an overview of G. milneedwardsi, and three new records of associations with ctenophores for G. milneedwardsi. New observations on the interaction of G. milneedwardsi with one of its ctenophore hosts, Mnemiopsis sp., are also documented.
Subject(s)
Amphipoda/classification , Amphipoda/anatomy & histology , Amphipoda/growth & development , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , California , Female , Male , Oceans and Seas , Organ SizeABSTRACT
This is the first comprehensive review of the genus Hyperoche since that of Bovallius (1889). This study is based primarily on the extensive collections of the ZMUC but also on more recent collections in other institutions. Seven valid species are recognised in this review, including one described as new to science. Two new characters were discovered; the first two pereonites are partially or wholly fused dorsally and the coxa of pereopod 7 is fused with the pereonite. These two new characters, combined with the knife-shaped carpus of the gnathopoda and the laminate mandibular molar, help to further distinguish this genus amongst the Hyperiidea. Partly as a result of establishing these distinctive characters, a new genus, Prohyperia gen. nov. is proposed for H. shihi Gasca, 2005 because it has characters not consistent with Hyperoche or the closely related genus Hyperia, to which it also bears some resemblance. Hyperoche medusarum and H. luetkenides, although morphologically similar, are considered separate species, with H. medusarum restricted to the colder waters of the northern Hemisphere and H. luetkenides to the Southern Ocean and Antarctic waters. Hyperoche cryptodactylus, still only known from the unique type, is considered a synonym of H. luetkenides because the character distinguishing it, the retractile dactyl of gnathopod 2, also occurs in some specimens of H. luetkenides and has also been found in other species of Hyperoche. Some specimens also have some pereopoda with partly or wholly retracted dactyls, although there is no pattern to the occurrence. In addition to the above the following species are also considered valid, H. martinezii, H. mediterranea and H. picta, found mainly in the tropical and temperate regions of the Atlantic and Pacific Oceans, and H. capucinus, restricted to the region between the Antarctic Polar Front and the Antarctic Continent. One new species, H. macrocephalus sp. nov., is described from the tropical eastern Indian Ocean and the Mediterranean Sea. All species are described and illustrated and a key is provided to facilitate their identification.
