Table 1.
Morphological characters of Paradexamineacuta sp. nov. and related species.
| Species Characters | P.gigas (♂) | P.houtete (♀) | P.jindoensis (♀) | P.marlie s.l. (♀) | P.micronesica (♂?) | P.acuta sp. nov. (♀) |
|---|---|---|---|---|---|---|
| Body length | 3.5 mm | 3.7 mm | 5.5 mm | 3.5 mm | 3.0 mm | 5.5 mm |
| Pleonites tooth formulae | 1-3-3-3-0 | 1-3-3-3-0 | 1-3-3-3-0 | 1-3-3-3-0 | 1-3-3-3-0 | 1-3-3-3-0 |
| 1-3-3-1 | ||||||
| Ocular lobe | acute | acute | acute | acute | acute | acute |
| Lower lip, corn | 1 cone | 2 cones | 2 unequal cones | 2 cones | 1 cone | 2 cones |
| Mandibular process | blunt, weakly developed | apically hooked | apically hooked | apically hooked | blunt, weakly developed | apically hooked |
| Mandible, accessory spines | no spine | 2 spines | 2 or 3 tiny spines | ? | no spine | 2 or 3 spines |
| Maxilla 1, palp | 5 apical setae | 8 setae | 6 apical setae | 7 apical setae | 5 apical setae | 11 apical setae |
| Maxilla 2, inner margin of inner plate | no seta | no seta | 5 setae | 4 setae | 4 setae | 5 setae |
| Maxilliped, inner plate | no lateral seta | no lateral seta | 7 lateral setae | no lateral seta | no lateral seta | no lateral seta |
| Maxilliped, outer plate | 11 conical teeth | 12 conical teeth | 16 conical teeth | 12 conical teeth | 11 conical teeth | 17 conical teeth |
| Antenna 1, articles 1 & 2 ratio | 1.0 : 1.5 | 1.0 : 1.1 | 1.0 : 1.5 | 1.0 : 1.1 | 1.0 : 2.0 | 1.0 : 1.3 |
| Gnathopod 1, interior setae of propodus | 4 setae | 5 setae | 8 setae | 9 setae | 4 setae | 10 or 11 setae |
| Gnathopod 1, carpus & propodus ratio | 1.0 : 0.9 | 1.0 : 0.9 | 1.0 : 0.9 | 1.0 : 1.3 | 1.0 : 1.0 | 1.0 : 0.9 |
| Gnathopod 2, carpus & propodus ratio | 1.0 : 0.7 | 1.0 : 0.8 | 1.0 : 0.9 | 1.0 : 0.8 | 1.0 : 0.5 | 1.0 : 0.9 |
| Pereopod 6, basis | tapering posterodistally | excavated posterodistally | roundly produced posteriorly | roundly produced posteriorly | slightly tapering posterodistally | roundly produced posteriorly |
| Coxa 7 | rounded posteroventrally | pointed posteroventrally | rounded posteroventrally | pointed posteroventrally | pointed posteroventrally | pointed posteroventrally |
| Pereopod 7, basis | subovate | subrectangular | subrectangular, narrow | subrectangular, narrow | elongate-ovate, moderate | subrectangular, narrow |
| Telson | cleft, roundish marginally, 1 lateral spine | slender and longish, 4 or 5 lateral spines | slender and longish, 14 or 15 lateral spines | elongate-ovate, 7 lateral spines | slender and longish, 2 lateral spines | slender and longish, 7 or 9 lateral spines |
| Distribution | Tomioka bay, Japan | New Zealand | Jindo Island, Korea | Tomioka bay, Japan | Tomioka bay, Japan | Korea |
| References | Hirayama, 1984 | Barnard, 1972b | Kim & Lee, 2008 | Hirayama, 1984 | Hirayama, 1984 | Present study |