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

3. Body dorsally compressed; frontal lamina slender,
shield-shaped or lanceolate; rostrum anteriorly
widely rounded or truncate; maxilliped palp 3articled
...........................................Rocinela [p. 6 ]
– Body dorsally moderately to strongly vaulted;
frontal lamina wide; rostrum narrowly rounded
or acute; maxilliped palp 5-articled .....................4
4. Rostrum anteriorly directed, acute; frontal lamina
ventrally flat, antennule peduncle articles 1 and
2 flattened; maxilliped palp article 5 wider than
long, partly or entirely fused to 4 ........................5
– Frontal lamina with free posterior margin and/or
posteriorly narrow; antennule peduncle articles
1 and 2 not flattened or expanded .......................6
5. Uropod rami co-planar; uropodal rami to or beyond
pleotelson apex; uropodal endopod lateral
margin without distinct excision; pleotelson lacking
distinct, usually produced point ............ Aega
– Plane of uropod endopod at oblique angle to
exopod, uropodal rami not extending to pleotelson
apex; uropodal endopod lateral margin
usually distinct excision; pleotelson apex forming
distinct, usually produced point ............................
......................................................Aegapheles [p. 65]
6. Rostrum bent ventrally or ventrally and posteriorly;
maxilliped palp article 5 longer than wide,
not fused to article 4 ...................Aegiochus [p. 83]
– Rostrum minute, not projecting, not visible in
dorsal view; maxilliped palp article 5 minute, less
than 0.3 width of article 4...........Epulaega [p. 5 ]
Genus Aega Leach, 8 5
Æga Leach, 8 5: 369; 8 8: 549; Desmarest, 825.– Milne
Edwards, 840: 238.– Dana, 852: 304*; 853: 747.–
Gosse, 855: 34.– Harger, 880: 383.– Haswell, 882:
284.– Bate & Westwood, 86 – 868: 276.– Miers, 876b:
08.– Schioedte & Meinert, 879b: 334.– Hansen, 890:
3 6.– Sars, 897: 58.– Richardson, 905a: 67.– Stebbing,
905: 20.– Hodgson, 9 0: 7.– Stephensen, 948: 36.
Aega.– Gerstaecker, 882: 227.– Barnard, 9 4: 36 ; 936:
57.– Hale, 925: 68.– Wahrberg, 930: 8.– Nierstrasz
& Schuurmans Stekhoven Jr, 930: e74.– Gurjanova,
933: 429; 936: 70.– Holthuis, 956: 4 .– Menzies, 962:
7.– Schultz, 969: 89.– Menzies & George, 972:
7.– Kensley, 978: 56.– Kussakin, 979: 23 .– Brusca,
983: 7.– Menzies & Kruczynski, 983: 62.– Bruce, 983:
757; 996: 29.– Brusca & Iverson, 985: 40.– Kensley
& Schotte, 989: 6.– Bruce, Lew Ton & Poore, 2002:
60.
Pterelas Guérin-Méneville, 836: VII.– Dana, 852: 204; Dana,
853: 748.
Æegacylla Dana, 854: 76.
Aega (Aega).– Brusca, 983: 0.
* There is a pagination error in this publication, with page
304 printed as 204.
27
type speCies: Oniscus psora Linnaeus, 758 (= Aega psora
(Linnaeus, 758); original orthography was Oniscus
Pforá; by subsequent designation, Menzies ( 962). Aega
emarginata (Leach, 8 5) is a junior synonym. Aega affinis
Milne Edwards, 840 was regarded as a synonym
of A. psora by Kussakin ( 979).
diagnosis: Body moderately to strongly dorsally
vaulted. Rostral point acute, anteriorly produced between
antennule peduncles. Eyes present, often large,
usually separate. Pleon not distinctly narrower than
pereonite 7, pleonite not abruptly narrower than
pleonite 2. Antennule peduncle articles 1 and 2 flattened,
often expanded with anterodistal angle of article
2 forming lobe, article 3 less than 0.3 H width of article
2. Frontal lamina wide, posterior margin not clearly
defined, lateral margins usually straight. Maxilliped
palp 5-articled; article 5 wide, often fused to article
4, distal margin convex, with slender setae; endite
present. Coxae 5–7 as long as or longer than respective
pereonite. Pereopods –3 merus inferior margin with
large robust setae, usually set as one or more rows.
desCription: Pleon not abruptly narrower than pereon;
pleonites all visible, not posteriorly widest, pleonite 5
laterally overlapped by pleonite 4; pleonites 3–5 posteriorly
produced to an acute point. Pleotelson large,
about as long as longer pleon, usually with PMS and
RS.
Mandible with uni- or bicuspid incisor; molar
process present, reduced or absent. Maxillule with 5–8
elongate, flat, narrow-based terminal and mesial RS.
Maxilliped 5-articled, article wider than long, articles
3 and 4 each with 2–6 stout recurved RS, article 5 with
2–7 occasionally hooked RS; endite present, usually
with –2 terminal setae.
remarks: Under the revised concept Aega sensu strictu
contains those species with a prominent, acute and
anteriorly projecting rostrum, the antennule peduncle
with articles and 2 strongly dorsoventrally
compressed, sometimes with an anterolateral lobe, a
slender peduncle article 3 (less than one-third as wide
as article 2), and the uropod peduncle with an elongate
mesial lobe that stretches most of the length of the uropodal
endopod. Species within Aega sensu strictu lack
a falcate uropodal endopod, although this is weakly
expressed in the type species; most species have matte,
punctate or pitted dorsal body surfaces.
Three species, A. magnifica (Dana, 854), A. maxima
Hansen, 897 and A. sheni yu & Bruce, 2006 lack the
slender antennule peduncle article 3 and have a clearly
falcate uropodal endopod, and approach some Aegapheles
in the appearance of the antennule and uropodal
endopod. These species are here regarded as incertae
sedis (see discussion of clades, p. 6– 9).