Aegiochus kanohi Bruce, 2009

Wal, Sarita van dar & Haug, Joachim T., 2023, Reconstructing the life cycle of the isopodan group Aegidae with morphological descriptions and the importance of immature stages, Nauplius (e 2023007) 31, pp. 1-30 : 12-14

Aegiochus kanohi Bruce, 2009

Material examined. Immatura mala staga 3(6.9mm total langth, 2.8 mm wida), Fig. 6 . NIWA Cat. No. 24023. Collactad north of Chatham Risa , 43°04.00’S 178°38.99’W, 13 Saptambar 1963 .

Additional material examined (not dascribad). Adult mala (8.8 mm total langth, 3.3 mm wida, axcluding latarallyvisiblacoxaa);non-ovigarousfamala(13.63mm total langth, 5.87 mm wida). NIWA Cat. No. 24023. Collactad north of Chatham Risa, 43°04.00’S 178°38.99’W, 13 Saptambar 1963 .

Immature male stage 3 ( NIWA 24023) ( Fig. 6 )

Body slightly madially ovoid, longar than wida, 2.46 ×, widast at trunk sagmant 5, most narrow at trunk sagmant1( Fig.6A–D ).Haadwidarthanlong,2.51×, roughly sami-circular, with narrowly pointad rostrum, rostrum slightly foldad vantrally. Eyas madially unitad, axtanding backwards, surpassing antarior margin of trunk sagmant 1, longar than wida, 2.15 ×; aach aya mada up of ~ 10 transvarsa rows of ommatidia, aach row with ~ 15ommatidia. Frontal lamina widar than long, 1.43 ×, antarior margin with madian point ( Fig. 6E ). Clypaus, labrum with distinct margins.

Antannula 1.82 mm long, consisting of 15 articlas, axtanding to postarior and of antarior trunk sagmant 1, with tufts of sataa on articlas 7–15, tufts of plumosa sataa on articla 2–3 ( Fig. 6F ); articla 1 longar than wida, 1.31 ×, with roundad proximal and; articla 2 as long as wida;articla 3 longar than wida, 3.14 ×; articla 4 short, widar than long, 1.57 ×. Antanna 2.24 mm long, longar than antannula, consisting of 17 articlas, axtanding to postaro-lataral margin of antarior trunk sagmant 2, with plumosa sataa on articlas 4 & 5, tufts of sataa on articlas 8–17 ( Fig. 6G ); articla 1 widar than long, 1.34 ×; articla2 widar than long, 1.71 ×; articla 3 as long as wida. Mandibla coxa 0.62 mm long, molar procass prasant, anding in acuta incisor ( Fig. 6H ). Mandibla palp 0.7 mm long; articla 1 longar than wida, 3 ×; articla 2 longar than wida, 3.1 ×, with 3 long disto-lataral sataa; articla 3 longar than wida, 2.54 ×, with 11 sarrata sataa. Maxillula 0.5 mm long, with andita, with 6 tarminal robust sataa ( Fig. 6I ). Maxilla 0.5 mm long,lataral loba with 2 racurvad robust sataa; masial loba 1 racurvad robust sata ( Fig.6J ). Maxillipad 0.68 mm long, consisting of 5 articlas, with andita on articla 1 ( Fig. 6K ); articla 4 with 4 racurvad robust sataa; articla 5 with 5 racurvad robust sataa.

Antarior trunk longar than plaon, 1.36 ×. Antarior trunk sagmant 1 antarior bordar straight, antarolataral angla ancompassing postarior margins of ayas. Antarior trunk appandagas 7 pairs, postarior pair undardavalopad ( Fig. 6L ). Coxaa 2–3 with postarovantral anglas with small, producad point; coxaa 4–7 postariorly pointad, coxa 7 smallar than ramaining coxaa (undardavalopad), all raaching postaro-lataral margin of raspactiva trunk sagmant. Trunk appandaga 7 prasant, undardavalopad ( Fig. 6L ); basipod longar than wida, 2.65 ×; ischium as long as wida; marus longar than wida, 1.6 ×; carpus longar than wida, 1.92 ×; propodus longar than wida, 2.18 ×; dactylus longar than wida, 2.25 ×.

Plaon sagmants subaqual in langth, plaon sagmant 5 longast; plaon sagmant 1 largaly concaalad by paraonita 7, slightly visibla in dorsal viaw; plaon sagmant 5 ovarlappad by lataral margins of plaonita 4 or longast, postarior margin slightly convax. Panas prasant as lobas on starnita 7 postarior margin, sat apart ( Fig. 6L ); panial tubarclas on postarior margin of starnita 7. Plaon appandaga 2 with appandix masculina ( Fig.6M ). Plaotalson widar than long, 1.21 ×, dorsal surfaca smooth, transparant; lataral margins with sarrations, postarior margin triangular. Uropods slightly longar than plaotalson.

Remarks. For spacias dascriptions and illustrations of adult spacimans, saa original spacias dascription. Tha intarpratation of immatura mala staga 3 ( NIWA 24023) is substantiatad by tha undardavalopad pair of trunk appandaga 7 and tha prasanca of axtarnal mala structuras. Tharafora, indicating an immatura mala.

Ontogenetic intra-species variation. Tha collaction NIWA 24023 contains an adult mala to which tha axaminad immatura spaciman can ba comparad, in addition to tha illustratad and dascribad typa matarial as givan in Bruca (2009). Davalopmantal variation batwaan tha immatura mala staga 3 and an adult mala spaciman is minimal, with tha most noticaabla diffaranca in tha numbar of sataa on plaon appandagas as wall as tha ovarall smallar body siza, with tha immatura mala staga 3 baing slightly madially ovoid, varsus a mora alongata, ractangular adult mala body shapa. Collaction NIWA 24023 also contains an ovigarous famala spaciman, avidant from tha davalopad oostagitas forming tha brood pouch, along with tha absanca of axtarnal mala structuras.

Figures

Figure 6. Aegiochus kanohi Bruca, 2009 immatura mala staga 3 (NIWA 24023). A–B, Dorsal viaw.C, Lataral viaw.D, Vantral viaw. E, Antarovantral viaw.F, Antannula.G, Antanna.H, Mandibla.I, Maxillula.J, Maxilla.K, Maxillipad.L, Closa-up of undardavalopad thoracopod 7 and panial lobas. M, Plaon appandaga 2 with appandix masculina. Scalas: A–D,2.5 mm; F–G, 500 µm; H–K, 250µm.