биота российских вод японского моря - Materials of Alexey Shipunov

setae; 3-segmented branch with 6 setae. Exopods of thoracic limbs 1–3 with 3–4 setae.Cauda formed of 2 triangular pointed outgrowths. Caudal setae situated on small tubercle.KEY TO THE SPECIES OF THE GENUS PLEOPIS1 (2). Exopod of limbs 1–3 with 4 setae, cauda with caudal claws covered with spinules................................................................................. 1. P. schmackeri (p. 15)2 (1). Exopod of limbs 1–3 with 3 setae, cauda in shape of pointed conical tubercles................................................................................... 2. P. polyphemoides (p. 16)1. Pleopis schmackeri (Poppe, 1889)(Pl. II, figs. 1–6)Poppe, 1889: 293–300; Yamazi, 1966: 192, pl. 88, fig. 3 (Podon schmackeri); Mordukhai-Boltovskoi,1978: 523–529, figs. 2, 3; Mordukhai-Boltovskoi & Rivier, 1987: 109–110,fig. 59; Rivier, 1998: 121–122, figs. 42–47 (Pleopis schmackeri).Description. Parthenogenetic female. Body rounded; head separated frombody by depression. Shell, containing brood pouch, semispherical. Swimming antennaeshort; terminal segment on each of 2 branches twice shorter than penultimate one;penultimate segment twice shorter than preceding one. Each exopod of limbs 1, 2, and3 bears 4 setae; that of limb 4 with only 2 setae. Fourth seta on exopod of limbs 1–3present among podonids only in P. schmackeri. Setal formula 4.4.4.2. Endopodsarmed with numerous setae, too. First segment of endopod of limb 1 with 7 setae oninner side; second segment with 2 short setae, twice shorter than apical ones. Maxillaryprocesses especially developed on limbs 2 and 3, with long pointed spines. Caudalclaws straight, thin, covered with clearly noticeable spinules. Caudal setae situatedon tubercle, together with small denticles.Height of parthenogenetic female from 0.45–0.65 mm to 0.87 mm (Kim & Onbe,1989a). Same authors present sizes of 2 almost rounded males: height 0.43 and0.46 mm, length 0.42 and 0.43 mm.Distribution. P. schmackeri has the narrowest geographical range among themarine podonids. It is distributed along the Asian coast from the south-eastern shoresof Indochina Peninsula (13°N) to the eastern coast of Korea (38°30′N). It is abundantin the bays north of Hong Kong, 22°30′N (Tang et al., 1995), inhabits the whole areaof the Korea Strait, and comes into the southern regions of the Sea of Japan (Kim &Onbe, 1989b). The species also migrates north along the Japan Islands to 40°N and tothe Pacific Ocean to 155°E (Kim & Onbe, 1989b).The species is rarely found in Peter the Great Bay; it was recorded only sporadicallyin the south-western part of the bay in July and August (Shkoldina & Pogodin,2001; Shkoldina et al., 2002).Biology and ecology. The development begins in April in the southernmostpoints of the distributional range. The species is most abundant in August; in Septemberand October only isolated specimens were found in the plankton. The most abundantpopulations (up to 100 sp./m 3 ) were recorded in the Korea Strait in August, andless numerous ones off the southern shores of Honshu Island and near Kii Peninsula15