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

Most species are loosely associated with sponges, but
Epulaega lethrina is unambiguously but not exclusively
a commensal of coral reef fishes (principally Serranidae
and Lethrinidae) on the Great Barrier Reef (Bruce
983). On present records the genus has an Indo-West
Pacific distribution to approximately 42° South in New
Zealand.
etymoLogy: From the Latin epulo (guest at a banquet or
feast), in combination with Aega to indicate the family
affinity. Gender feminine.
Key to the new Zealand species of epulAegA
Posterior margin of pereonites without nodules;
dorsal surfaces of pleotelson smooth ....................
...................................................E. derkoma sp. nov.
– Posterior margin of pereonites with small nodules;
dorsal surface of pleotelson with scattered small
spines .............................................E. fracta (p. 56)
Epulaega derkoma sp. nov. (Figs 92–95)
materiaL: Holotype: ♀ (ovig. 7.7 mm), South Norfolk
Basin, 25 July 975, 32° 0.80’S, 67°2 . 9’E, 356 m, DR
Stn I96 (NIWA 23862).
desCription: Body .4 times as long as greatest width,
dorsal surfaces polished in appearance, widest at pereonite
5, lateral margins weakly ovate. Rostral point
ventrally directed. Eyes large, medially united (line of
separation present), anterior clear field 17% length of
head, posterior clear field 20% length of head; each eye
made up of ~9 transverse rows of ommatidia, each row
with ~7–8 ommatidia; eye colour dark brown (chestnut).
Pereonite 1 and coxae 2–3 each with posteroventral
angle right-angled; posterior margins of pereonites not
ornamented (posterior of pereonites 2 and 3 with weak
submarginal transverse ridge). Coxae 5–7 with entire
oblique carina (weakly defined) posterior margins
convex, posterolateral angle blunt (more than 45°).
Pleon with pleonite largely concealed by pereonite 7;
pleonites with lateral margin of pleonites 4–5 plate-like
and flattened; 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 0.7 times as long
as anterior width, dorsal surface without longitudinal
carina; lateral margins convex, smooth, posterior margin
converging to caudomedial point, with RS rubbed
off, only remaining.
Antennule peduncle articles 3 and 4 . times as long
as combined lengths of articles and 2, article 3 3.4
times as long as wide; flagellum with 9 articles (article
0.9 times as long as peduncle), extending to anterior
of pereonite . Antenna peduncle article 4 2.3 times as
52
long as wide, 0.9 times as long as combined lengths of
articles –3, inferior margin with plumose seta and
2 short simple setae (distal); article 5 .4 times as long
as article 4, 4.3 times as long as wide, inferior margin
with pappose seta, anterodistal angle with cluster
of 1 short simple seta (and 1 pappose seta); flagellum
with 2 articles, extending to posterior of pereonite 3.
Frontal lamina flat, longer than greatest width, lateral
margins converging posteriorly, anterior margin
rounded, without small median point, posterior margin
not abutting clypeus.
Mandible molar process present, small distinct flat
lobe; palp article 2 with 0 distolateral setae (in two
tiers, 4 biserrate, 4 stout simple, 2 slender simple),
palp article 3 with 20 setae (terminal less than twice
as long as remainder). Maxillule with 6 terminal RS (
large, 3 slender, 2 minute). Maxilla mesial lobe with 2
RS (circumplumose); lateral lobe with 2 RS (curved).
Maxilliped palp article 2 fused to article 3; article 3 with 3
straight RS; article 4 with 2 straight RS; article 5 wholly
fused to article 4, with RS.
Pereopod 1 basis 3.9 times as long as greatest width;
ischium 0.5 times as long as basis, inferior margin with
RS (small), superior distal margin with RS; merus
inferior margin with RS (plus 2 slender setae), set as
distal group, superior distal angle with RS (small);
carpus 0.4 as long as merus; inferior margin with 0 RS;
propodus 2. times as long as proximal width, inferior
margin with 0 RS, propodal palm simple, without
blade or process, dactylus smoothly curved, .0 as
long as propodus. Pereopod 2 ischium inferior margin
with RS (large blunt), superior distal margin with
RS; merus inferior margin with 5 RS (large, blunt;
set as , 2 and 2), set as three groups, superior distal
margin with 2 acute RS; carpus similar in size to that
of pereopod , inferodistal angle with 0 RS. Pereopod 3
similar to pereopod 2. Pereopod 6 similar to pereopod
7. Pereopod 7 basis 3.0 as long as greatest width, inferior
margins with 4 palmate setae; ischium 0.4 as long as
basis, inferior margin with 2 RS (set as and ), superior
distal angle with 3 RS, inferior distal angle with 3
RS; merus 0.9 as long as ischium, .7 times as long as
wide, inferior margin with 2 RS (set as and ), superior
distal angle with 6 RS, inferior distal angle with 3
RS; carpus .0 as long as ischium, 2.0 times as long as
wide, inferior margin with RS, superior distal angle
with 8 RS (5 biserrate), inferior distal angle with 4 RS;
propodus . as long as ischium, 4.0 times as long as
wide, inferior margin with 2 RS (set as single cluster),
superior distal angle with slender seta, inferior distal
angle with 2 RS.
Pleopod 1 exopod 2.0 times as long as wide, lateral
margin weakly convex, mesial margin strongly convex,
with PMS from distal half, with ~34 PMS; endopod 2.
times as long as wide, distally rounded, lateral margin
straight, with PMS from on distal margin only, mesial