The Marine Fauna of New Zealand: Isopoda, Aegidae (Crustacea)

New figures of the holotypes of Aegiochus crozetensis
and A. uschakovi are given (Appendix 2; Figs 4 , 45
respectively). A. pushkini has a far shorter antennule
flagellum, figured as extending only to the anterior of
pereonite . Aegiochus uschakovi, at 8 mm, is substantially
larger than A. gordoni, and is figured as having
the posterior coxae far more strongly produced, the
antennule flagellum with 15 articles (10 in A. gordoni),
antennal flagellum with 19 articles (11 in A. gordoni)
and the propodal palm as lacking setae. Examination
of the type material of these Southern Ocean species
confirms that they are all distinct from A. gordoni.
The deeply serrate pleopod exopod is not unique
to A. gordoni, and has been figured for several other
New Zealand species, the most similar being Aegiochus
coroo and Aegiochus laevis. Aegiochus coroo has the eyes
united, and a more rounded and notched posterior
margin to the pleotelson. There are further similarities
between these three species in the unarmed pleotelson,
a large molar process on the mandible, maxillule lateral
lobe which has one prominently large and several small
robust setae (in contrast to the more usual three large
and several small terminal setae) and the anterior pereopods
with very few and small robust setae. Aegiochus
laevis is small, and readily separated from A. gordoni by
having small eyes, somewhat similar in size to those
of cirolanids.
prey: Not known.
distribution: Recorded from the Chatham Rise to the
east of South Island and Brothers Sea Mounts to the
northeast of North Island; at depths from 360 to 40
metres (the minimum depth was recorded from a haul
that ran from 360 to 755 metres, all other records are
from 698 metres or greater).
etymoLogy: Named for Dennis Gordon, scientist,
natural historian, biological enthusiast and untiring
advocate for taxonomic research in New Zealand—in
recognition of his huge direct and indirect contribution
to knowledge of the New Zealand marine fauna.
Aegiochus insomnis sp. nov. (Figs 56–60)
materiaL: Holotype: ♂ (6.9 mm) Poor Knights Islands,
pass south of landing, 9 May 969, 33–37 m, from
sponge and [bryozoa], SCUBA (AK 73308).
Paratypes: 2 ♀ (ovig. 7.2, 7.8, 8.0 [dissected], 8.4, 9.0,
9.5; non-ovig. 6.5, 6.8, 7.0, 7.5, 8.4, 9.0 [dissected] mm),
same data as holotype (AK 73309; NIWA 28462 [2]).
desCription: Body 2.2 times as long as greatest width,
dorsal surfaces polished in appearance and sparsely
punctate, widest at pereonite 5, lateral margins ovate.
Rostral point folded ventrally and posteriorly. Eyes
large, not medially united, separated by about 23%
width of head; each eye made up of ~ 0 transverse
rows of ommatidia, each row with ~8 ommatidia; eye
colour red. Pereonite 1 and coxae 2–3 each with posteroventral
angle right-angled (point soft, not abrupt).
Coxae 5–7 with entire oblique carina; posterior margins
straight and sinuate (coxa 7 is sinuate), posterolateral
angle acute (less than 45°) (coxa 5 not acute). Pleon with
pleonite largely concealed by pereonite 7; pleonite 4
with posterolateral margins not extending to posterior
margin of pleonite 5; pleonite 5 with posterolateral
angles free, not overlapped by lateral margins of pleonite
4. Pleotelson 0.8 times as long as anterior width,
dorsal surface without longitudinal carina; lateral margins
convex, serrate, posterior margin evenly rounded,
with 0 RS.
Antennule peduncle articles 3 and 4 . times as
long as combined lengths of articles and 2, article
3 3.1 times as long as wide; flagellum with 8 articles,
extending to posterior of pereonite . Antenna peduncle
article 4 2.0 times as long as wide, 0.8 times as long
as combined lengths of articles –3, inferior margin 0
plumose setae, and 0 short simple setae (anterodistal
angle with 5 long simple setae); article 5 .2 times as
long as article 4, 2.6 times as long as wide, inferior margin
with 2 palmate setae (at distal angle), anterodistal
angle with cluster of 4 short simple setae (long simple
setae, and 1 pappose seta); flagellum with 13 articles,
extending to posterior of pereonite 2.
Frontal lamina flat, longer than greatest width, diamond
shaped, anterior margin acute, without small
median point or forming median angle, posterior
margin not abutting clypeus.
Mandible molar process present, small distinct flat
lobe; palp article 2 with 5 distolateral setae (3 biserrate,
2 simple), palp article 3 with 3 setae (serrate; distal 3
markedly longer than remainder). Maxillule with 5 terminal
RS ( large, 4 slender). Maxilla mesial lobe with 2
RS ( biserrate); lateral lobe with 3 RS. Maxilliped endite
with 0 apical setae; palp article 2 with 2 RS (slender);
article 3 with 4 straight RS; article 4 with 4 hooked RS
(and simple seta); article 5 with 3 RS ( large, and 2
small slender).
Pereopod 1 basis 2.6 times as long as greatest width;
ischium 0.3 times as long as basis, inferior margin
with 0 RS, superior distal margin with RS; merus
inferior margin with RS (plus 2 short and long
simple setae), set as distal group, superior distal angle
with 0 RS ( simple seta); carpus 0.8 as long as merus,
inferior margin with RS; propodus 2.6 times as long
as proximal width, inferior margin with 2 RS (set as
minute and distally), propodal palm simple, without
blade or process, dactylus smoothly curved, 0.9 as long
as propodus. Pereopod 2 ischium inferior margin with
0 RS, superior distal margin with RS; merus inferior
margin with 3 RS (set as and 2; 2 simple setae), set
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