“Jassa hartmannae n.sp.
Adult male, major form
Holotype: length 4.5 mm. Antenna 1: overlaps antenna 2 to about 3/4 along the length of peduncular segment 5. Antenna 2: segment 5, posterior margin bearing simple filter setae only, these about as long as those of juvenile; flagellum of 5 segments, the last minute, segment 1 is 36% of flagellum length. Mandible: palp segments 2 and 3 without dorsal fringe of setae; raker spines 3 right, 4 left. Maxilla 1: palp without setae at base of segment 1, segment 2 with 1 row of facial setae. Gnathopod 1: coxal margins, anterior 100% of dorsal length; ventral margin slightly concave; basis, anterior margin fringed with short, spinelike setae, posterior margin with 1 single setal cluster at junction with ischium; carpus, posterior lobe 42% of anterior margin length, without anterodistal setal cluster; propodus, palm straight; dactyl cusped along most of posterior margin, without facial striations. Gnathopod 2: coxal margins, anterior 32% and posterior 58% of ventral length; ventral margin sinuous; gill very small; basis, anterolateral flange with 11 short simple setae (setae about 1/4 segment width); carpus, posterior lobe without a distal seta; propodus, anterior margin with short setae proximally (setae about 1/4 basis width), palmar setae confined to hinge tooth area, thumb 21% of propodus length, distally squared, posterior margin shallowly concave to defining setae, defining setae closely approximated and accompanied by 3 spines; dactyl, inner margin expanded at location of hinge tooth. Peraeopod 3: coxa, greatest depth posterior of centre; basis, anterior margin straight; merus, anterior margin fringed with single, evenly spaced setae about 1/3 segment width, segment width 90% of length; carpus 90% overlapped by merus; propodus, width 63% of length. Peraeopods 5-7: propodus not expanded anteriorly; dactyl without a fringe of short setae along anterior margin, without facial striations. Pleopods: with 2 peduncular coupling hooks. Uropod 1: peduncle, posteroventral spinous process underlying 50% of inner ramus, inner and outer rami with 4 and 5 marginal spines, respectively, terminating in a fringe of cusps ventral to apical spine group. Uropod 2: peduncle, posteroventral spinous process underlying 14% of inner ramus. Uropod 3: outer ramus with 2 sequential cusps proximal to basally immersed, dorsally recurved spine, smaller cusps in area of large cusps, and 1 seta originating at insertion of recurved spine; inner ramus with only the single apical spine. Telson: setose only at lateral cusps.
Condition
Without left peraeopod 5. Right antennae 1, right and left antennae 2, right gnathopods, peraeopods 3-7, pleopods, uropods, left peraeopods 5 and 7, telson, and mouthparts slide mounted. Other appendages with the carcass.
Adult female
Allotype: length 3.6 mm. Antenna 2: segment 5 without plumose setae. Gnathopod 1: coxa, ventral margin straight. Gnathopod 2: coxal margins , anterior 47% and posterior 94% of ventral length; ventral margin straight; propodus, hinge tooth pronounced, palmar setae not abundant, palmar angle acute, distal, but close to defining spines; dactyl, inner margin shallowly expanded at position of hinge tooth, tip fitting into depression between palmar angle and defining spines.
Condition
Ovigerous. Without left peraeopods 4-7 and right peraeopods 5-7. Right antenna 2, gnathopods 1 and 2, peraeopod 3, and uropods 1-3 slide mounted.
Variation
Body length at maturity: male 3.1-4.5 mm, female 3.6 mm. All known thumbed males have defining spines; however, these are not strongly pronounced as in J. ingens or J. morinoi, so they may be lost in larger males. Variation of the male's second gnathopod is illustrated in Figs. 3-6.
Type material: Holotype: male (AM), type No. P34950, station No. SA-3492, New Zealand: The Snares: Senecio Pool (48°07'S, 166°38'E), 6 January 1977, from Lessonia variegata holdfast, 1.5 m, G. D. Fenwick, collector. Paratypes: 2 adult males, type No. P37919, same location. Allotype: female (USNM), type No. USNM 235008, accession No. 149461, station No. E973 (J. L. Barnard, station NZ-8), New Zealand: South Island: Dunedin: St. Clair (45°50'S, 17°20'E), formalin wash of algae, especially of pterocladians or streblocladians, heavy turf (Gelidium–Bostrychia), and several specimens of Pyura sp. , J. L. Barnard, collector. Paratypes: 1 adult male, 2 ovigerous females, 9 juveniles, type No. USNM 235009, same location.
Remarks
Jassa hartmannae is a very small-bodied species. It joins the J. alonsoae, J. justi, J. fenwicki group in having a fringe of short setae along the anterior margin of the basis of gnathopod 1. The lack of a seta on the anterodistal junction of the carpus and propodus of gnathopod 1, and the fringe of short setae on the basis of gnathopod 2 distinguish this from sympatric species. Jassa hartmannae was confused as J. falcata by J. L. Barnard (1972).
Etymology: Named in honour of Dr. G. Hartmann, who lent numerous specimens for this study.”
(Conlan, 1990: 2049-2050)
