Harris: Male antennule of porcellidiid copepods 
149 
Table 1. Difference in body size and number of eggs carried by the female in A. edenensis collected from northern New 
South Wales, Australia (latitude 30°S) and cooler temperate waters of southern NSW (latitude 37°S). 
Latitude 30°S 
Latitude 37°S 
N = 20 
N = 26 
L U rs mean 
0.64 mm, range 0.59-0.69 mm 
0.75 mm, range 0.72-0.81 mm 
W mean 
0.42 mm, range 0.40-0.45 mm 
0.50 mm, range 0.45-0.53 mm 
Rmean 
0.115 mm 
Ratios 
0.135 mm 
Lurs/W 
1.5 
1.53 
W/R 
3.7 
3.65 
Number of eggs 
mean 5, range 4-6 
mean 8, range 6-12 
and setation of mouth parts and ambulatory limbs typical of 
family. Antenna (Fig. 25A) with row of triangular setules on 
basis, five plumulose setae plus one finely serrulate spinous 
seta on exopod, segment 2 of endopod with three lateral 
setae, end part of geniculate setae plain, terminal claw 
comb-like, long. Mandibular palp without setules on anterior 
lobe. Maxillule, maxilla and maxilliped as described for A. 
bipunctatus. No peg area on PI endopod. Serrulate spinous 
seta on segment 3 of P2 endopod shorter than endopod 
(0.75:1) (Fig. 24D). P3 with internal seta on segment 1 of 
endopod, serrulate spinous seta on segment 2 of P3 endopod 
(Fig. 24A) shorter than endopod, large serrate spinous seta 
on segment 3 longer than endopod (1.37:l).Endopod of P4 
with internal seta on first segment, plain spinous seta on 
segment 2 and first (internal) seta of segment 3 (Fig. 24E). 
Exopod of P5 lanceolate, truncated posteriorly, two dorsal 
setae, one very small and one larger sub-terminal, one apical 
seta, dorsal surface with pits (Figs 23G, H). See Remarks 
for number of eggs carried by the female. 
Adult males (Fig. 23D) colourless. Anterior of cephalo- 
some truncated semi-ellipse, no medial bulge above rostrum 
or lens-like body in rostrum, shoulders rounded. Caudal 
ramus (Fig. 23C) quadrate, medial edge straight, lateral 
edge slightly convex, T2 and T3 very close, T4 set in from 
medial corner, terminal fringe of fine setules. Antennule 
(Figs 25C), no plumose setae on segment 2, anterior lobe 
on segment 3 extended as long finger-like process bearing 
5 and S' setae, no ventral process or blade on segment 3, 
two elongate coupling denticles with comb-like edge on 
segment 4 project forward parallel to anterior lobe, distal 
denticle small with pinnate seta, small pointed structure in 
“palm” of segment 4 (Fig. 25G), dactylus almost as long 
as segment 3+4 with characteristic deep indentation on its 
posterior edge, hooked terminally (Figs 25B, G). Endopod of 
P2 with two plumose setae on terminal segment (Fig. 24B). 
All setae on P4 endopod plumose, not spinous (Fig. 24C). 
P5 trapezoid, no setules at base of terminal setae except first 
or lateral seta (Fig. 25D). Spermatophore extremely small 
(about 12% of body length). 
Etymology. The specific name refers to Eden NSW where 
the species was first discovered. 
Remarks. A difference in body size and number of eggs 
carried by the female has been noticed between animals 
collected from northern NSW and those found in cooler 
temperate waters of southern NSW (Table 1). 
Distribution. Acutiramus edenensis has a wide geographical 
range covering more than 7° of latitude. The type series was 
collected from mixed seaweeds (including Ecklonia radiata) 
in the infralittoral fringe, Woolgoolga (30°03'S), Wo3. 
11/82, 35 (19 ovigerous), 17 SS plus 4 SS coupled to 
juveniles, 13 juveniles. It has been found at Broulee, NSW, 
(35°52'S) on Caulerpa sp., and in washings from Ecklonia 
radiata holdfasts at Twofold Bay, Eden, NSW, (37°06'S), 
TB4. 12/82, 11 3 <J<?, V. A. Harris 1982. 
Acutiramus iwasakii sp. nov. 
Figs 26, 28, 29 
Type material. Holotype adult male, length 0.54 mm, 
mounted on slide [1360], P88555; allotype adult female 
without egg mass, length 0.70 mm, mounted on slide [939], 
P88556 deposited at AM, Sydney; additional paratypes 
deposited atNHM, London. All collected from inside Turbo 
torquatus shells inhabited by hermit crabs of the species 
Pagurus sinuatus , O’Hara Head, Kioloa, NSW (25°34'S 
150°25'E, estimated), V. A. Harris, 1976. 
Diagnosis. Female rostrum unique, anterior edge with 
three curves giving an undulating appearance (Fig. 26D), 
hyaline border present; male rostrum with anterior point, not 
obscured by cephalosome above; setae on male antennule 
sensory lobe and dactylus extremely long (> than length of 
antennule); female caudal ramus rhomboid with pinnate T4 
at posterior apex, setules down length of medial edge, gap 
between y and T2 equals gap between T3 and T4, a and 
P setae close (% of ramus length apart); seta T1 on male 
caudal ramus very small; female genital double-somite with 
short cleft between anterior and posterior lobes; P3 endopod 
without seta on segment 1 (0:2:1, 3,1); P4 endopod without 
seta on segment 1 (0:1:1, 2, 1). 
Biometric data. Females (N = 6): maximum length (L m ax) 
mean 0.72 mm, length to posterior of genital double-somite 
(L U rs) mean 0.66 mm; width of cephalosome (W) 0.50 mm; 
rostrum width (R) 0.10 mm; genital double-somite length 
0.13 mm, width 0.22 mm, arch 0.09 mm; caudal ramus length 
0.08 mm, width 0.04 mm. 
Ratios: L m ax/W 1.45, L U rs/W 1.35; cephalosome W/R 5.0; 
genital double-somite width 44% of cephalosome width, w/1 
1.7, arch/1 0.7; caudal ramus 1/w 2.0, ramus as % of L m ax 
13%, Hicks’ index for a 83%, (3 67%, a-|317%. 
Males (N = 4): maximum length 0.54 mm; cephalosome 
width 0.40 mm; antennule 0.126 mm; angle of P5 apex 45°. 
Ratios: Caudal ramus 1/w 0.78, Hicks’ index for a 60%, p 
50%, a-P 11%; antennule 23% of Lmax, segment 3+4 43%, 
dactylus 16% of antennule length. 
