Species Of Gammaridean Amphipods Research Articles

Shallow water marine gammaridean amphipods of Pulau Tioman, Malaysia, with the description of a new species

Eleven taxa including one new species of gammaridean amphipods are reported from the waters of Pulau Tioman. The presence of Tethygeneia sunda sp. n. represents the first record of the genus from the South China Sea. Additional material of Ampelisca brevicornis (Costa, 1853); Cymadusa vadosa Imbach, 1967; Paradexamine setigera Hirayama, 1984; Ericthonius pugnax (Dana, 1853); Leucothoe furina (Savigny, 1816); Microlysias xenokeras (Stebbing, 1918); Monoculodes muwoni Jo, 1990 are identified from the South China Sea, supporting previous records by Lowry (2000), Huang (1994), Imbach (1967), Margulis (1968) and Nagata (1959). Three additional species, Gitanopsis pusilla K.H. Barnard, 1916, Liljeborgia japonica Nagata, 1965b and Latigammaropsis atlantica (Stebbing, 1888), whilst previously reported from the neighbouring waters, comprise new records for the South China Sea.

New Record of Two Species of Ampelisca (Crustacea: Amphipoda: Ampeliscidae) from Korea

Two species of gammaridean amphipod are newly recorded from the shallow Korean waters; Ampelisca alatopedunculata Ren and A. miharaensis Nagata. These are described and figured in detail. A key to the Korean Ampelisca species is provided.

Gammaropsis utinomii New to Korea (Crustacea: Amphipoda: Photidae)

Gammaropsis utinomii (Nagata, 1961), an incompletely known species of gammaridean amphipod, is redescribed in detail based on the specimens from the southern coast of Korea. The expanded basis of pereopod 7 of this species allows it to be distinguished from its congeners.

New and unusual abyssal gammaridean Amphipoda from the north-east Pacific

Seventeen species of gammaridean amphipods were identified from sediment trap collections in the north-east Pacific, off the central California coast from depths of 3450–4050 m. Four new monotypic genera, Anisocallisoma (Family Scopelocheiridae), Triquetramana (Family Eusiridae), Octomana and Macroarthrus (Family Pardaliscidae) and eight new species, Cyphocaris latirama, Schisturella spinirama, Paracallisoma spinipoda, Anisocallisoma armigera, Triquetramana brevipalpa, Octomana hadromischa, Macroarthrus victoriae, Oedicerina denticulata are described. A number of new and unusual morphological characteristics were discovered, most notably in the family Pardaliscidae, where two of the new genera belong. In addition, new distributional and/or depth records are established for the following species: Procyphocaris indurata (K. H. Barnard, 1925), Scopelocheiropsis abyssalis Schellenberg, 1926a, Rhachotropis distincta (Holmes, 1908), Cleonardo biscayensis Chevreux, 1908b, Cleonardo macrocephala Birstein and Vinogradov, 1955, Pardaliscopsis tenuipalpa Chevreux, 1911, Halice aculeata Chevreux, 1912 and the genus Oedicerina Stephensen, 1931. In order to assist future identification, the new species are fully diagnosed and illustrated. Three tables for comparing characters and a key to the species of Oedicerina are also provided. Additional morphological information and figures are given for existing species that hitherto were poorly described and illustrated. Sediment traps normally employed in studying organic matter fluxes are herewith used for the first time as a source of deep-sea amphipods, and this potentially exciting method is discussed. The high proportion of new taxa illustrates the deficiencies in our knowledge of the abyssal fauna in this area, emphasizes the importance of continued collecting in the deep-sea, and demonstrates the need for increased taxonomic effort to document this diversity.

Ultrastructural Evidence for Osmoregulatory Function of the Sternal Epithelia in Some Gammaridean Amphipods

The ion-permeabilities and the ultrastructure of the sternal epithelia were studied in 7 species of gammaridean amphipods. Evidence has been obtained that the sterna can be divided into 2 categories: ion-transporting and non-ion-transporting types. The sterna of Sternomoera japonica, Grandidierella japonica, Melita setiflagella, and Corophium uenoi, belonging to the former category, are covered by ion-permeable cuticular layers lined with a thick epithelium, which is characterized by both a shallow apical infolding system (AIS) and a well-developed basolateral infolding system (BIS). The AIS is composed of frequent lamellar infoldings without mitochondrial association originating from the apical sides of the epithelia and involves virtually every part of the apical cell membrane, forming elaborate intercellular channels in the subcuticular space. In contrast, the BIS consists of deep infoldings of the basolateral cell membranes and extensive interdigitations between epithelial cells, which are both associated with a large number of mitochondria. This BIS involves the greater part of the cell membrane and constitutes a complicated, giant labyrinth of the intercellular spaces above the basal lamina. The AIS and BIS never communicate in the sternal epithelia, though they sometimes interpenetrate. On the other hand, the sterna of Jesogammarus jesoensis, Jesogammarus hinumensis, and Haustorioides sp., belonging to the latter category, are composed of an ion-impermeable, thick cuticular layer and a thin epithelium characterized by a paucity of mitochondria and complete lack of the BIS and AIS, which are common to those of the ordinary epithelium of the body surface. The results suggest a rather widespread occurrence in amphipods of a variety of extrabranchial ion-permeable areas of the body surface. They also suggest that the sterna lined with thick, specialized epithelia, together with the gills, are involved in the active transport of electrolytes in osmoregulation as well as respiration.

ULTRASTRUCTURAL EVIDENCE FOR OSMOREGULATORY FUNCTION OF THE STERNAL EPITHELIA IN SOME GAMMARIDEAN AMPHIPODS

ABSTRACT The ion-permeabilities and the ultrastructure of the sternal epithelia were studied in 7 species of gammaridean amphipods. Evidence has been obtained that the sterna can be divided into 2 categories: ion-transporting and non-ion-transporting types. The sterna of Sternomoera japonica, Grandidierella japonica, Melita setiflagella, and Corophium uenoi, belonging to the former category, are covered by ion-permeable cuticular layers lined with a thick epithelium, which is characterized by both a shallow apical infolding system (AIS) and a well-developed basolateral infolding system (BIS). The AIS is composed of frequent lamellar infoldings without mitochondrial association originating from the apical sides of the epithelia and involves virtually every part of the apical cell membrane, forming elaborate intercellular channels in the subcuticular space. In contrast, the BIS consists of deep infoldings of the basolateral cell membranes and extensive interdigitations between epithelial cells, which are both associated with a large number of mitochondria. This BIS involves the greater part of the cell membrane and constitutes a complicated, giant labyrinth of the intercellular spaces above the basal lamina. The AIS and BIS never communicate in the sternal epithelia, though they sometimes interpenetrate. On the other hand, the sterna of Jesogammarus jesoensis, Jesogammarus hinumensis, and Haustorioides sp., belonging to the latter category, are composed of an ion-impermeable, thick cuticular layer and a thin epithelium characterized by a paucity of mitochondria and complete lack of the BIS and AIS, which are common to those of the ordinary epithelium of the body surface. The results suggest a rather widespread occurrence in amphipods of a variety of extrabranchial ion-permeable areas of the body surface. They also suggest that the sterna lined with thick, specialized epithelia, together with the gills, are involved in the active transport of electrolytes in osmoregulation as well as respiration.

Oxygen-binding by haemocyanins from an ecological series of amphipod crustaceans

The oxygen-binding properties of haemocyanins (Hc) from three species of gammaridean amphipods, Gammarus locusta (L.) (subtidal), Echinogammarus pirloti (Sexton and Spooner), (intertidal, marine) and E. marinus (Leach) (intertidal, estuarine), one species of hyalid amphipod Hyale nilsonni Rathke (high intertidal, marine) and the talitrid amphipod Orchestia gammarellus (Pallas) (semi-terrestrial) have been studied. All the species were collected from the Firth of Clyde, Scotland, during the spring of 1992. The oxygen-carrying capacity of haemolymph from each species was low, although variable, and was correlated with the low concentration of Hc present. The Hc oxygen-affinity of native gammarid haemolymph was relatively high [partial pressure of oxygen required for half-saturation, P50=4 to 5 torr (0.53 to 0.67 kPa)] at their respective in vivo pH values. At equivalent pH, however, Hc from G. locusta displayed a lower O2-affinity than either Echinogammarus species. Gammarid Hcs had a large Bohr effect (Δ log P50/Δ pH=-1.16 to-1.47). Resuspended Hc isolated from whole H. nilsonni showed similar O2-binding properties to those of the gammaridean amphipods [P50=6.3 torr (1.44 kPa) at pH=8.0; Δlog P50/ΔpH=-1.20]. Comparable data for haemolymph from O. gammarellus showed that the Hc had a lower affinity for O2 [P50=14.1 torr (1.87 kPa) at in vivo pH] and exhibited a more moderate Bohr effect (Δ log P50/Δ pH=-0.79). To eliminate the possibility that these differences were due to the different haemolymph constituents, each of the Hcs were pelleted and resuspended in physiological saline. The differences noted above persisted, demonstrating that they were due to inherent O2-binding properties of the Hc molecules themselves. An increase in L-lactate resulted in an increase in Hc oxygen-affinity for both Echinogammarus species but not for O. gammarellus. This study has confirmed that there is a clear difference between Hcs from aquatic and semi-terrestrial amphipod genera. The results lend further support to the hypothesis that the move on to land by amphipod crustaceans is accompanied by a decrease in Hc oxygen-affinity, a decrease in the Bohr effect and a decrease in effector (in this case L-lactate) sensitivity.

Rakiroa, a new amphipod genus from The Snares, New Zealand (Gammaridea, Corophiidae)

Summary Rakiroa rima, a new genus and species of gammaridean amphipod, is described from islands in the New Zealand subantarctic area. The diagnosis of the family Corophiidae is amended to accept the new genus.

Haustoriid amphipods (Crustacea) from India

4 species of gammaridean amphipods belonging to the family Haustoriidae are described from the southern Indian region. One among these, namely Urothoe platydactyla, is considered new.

Two new Gammaridean Amphipods (Crustacea) from the Gulf of Mannar, S. India

Two new species of Gammaridean Amphipods are described from the coastal waters of south India. Affinities with related forms are discussed.

On a Collection of Isaeidae (Crustacea, Amphipoha) from the Southern Indian Region

Nine species of gammaridean amphipods, belonging to the family Isaeidae, are fully described and figured. Eight of these were collected from typical marine locations on the East and West coast of South India and one, namely Photis digitata K. H. Barnard, 1935, was obtained from a brackish water lake on the West coast of peninsular India between 9°7' and 9°16' N and 76°20' and 76°28' E. Five of the species described are already known from the Indian coasts; one species, Eurystheus digitatus Schellenberg, 1938, is a new record for the region; two others (Microprotopus bicuspidatus and Eurystheus anomalus) are new to science. Until more materials become available, the last species included in this report is provisionally assigned to the genus Megamphopus Norman and is described without a specific name.