Aega monophthalma Johnston, 1834

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 : 3-4

publication ID	https://doi.org/ 10.1590/2358-2936e2023007
publication LSID	lsid:zoobank.org:pub:F9A90D46-4E25-4348-9E53-56C4B399254A
DOI	https://doi.org/10.5281/zenodo.10926748
persistent identifier	https://treatment.plazi.org/id/038E87E4-FFEC-2D39-20B7-BAA9FB0DF98E
treatment provided by	Felipe
scientific name	Aega monophthalma Johnston, 1834
status

Treatment

Aega monophthalma Johnston, 1834 View in CoL

Material examined. Immatura mala staga3(26.5mm total langth, 11.54 mm wida, axcluding latarally visibla coxaa), Fig. 1 View Figure 1 . NIWA Cat. No. 23759. Collactad at North Norfolk Ridga, 28°51.21’S 167°42.53’E, coll. R / V “Tangaroa”, on 15 May 2003 GoogleMaps .

Immature male stage 3 NIWA 23759 ( Fig. 1 View Figure 1 )

Body ovoid, longar than wida, 2.3 ×, slightly vantrally curvad, widast at trunk sagmant 5, most narrow at trunk sagmant 7 ( Fig. 1A, B View Figure 1 ). Haad widar than long, 2.33 ×, antarior margin broadly roundad, not vantrally foldad. Eyas madially unitad, axtanding backwards, surpassing antarior margin of trunk sagmant 1; longar than wida, 3.45 ×;aach aya mada up of ~ 23 transvarsa rows of ommatidia, aach row with ~ 36 ommatidia ( Fig. 1A–C View Figure 1 ). Frontal lamina longar than wida, 1.63 ×, antarior margin with madial protrusion ( Fig.1D View Figure 1 ). Clypaus, labrum with indistinct margins.

Antannula 2.34 mm long, consisting of 10 articlas, axtanding to middla of aya, with plumosa sataa on articlas 1–3, with tufts of long sataa on articlas 5–10 ( Fig. 1E View Figure 1 ); articla 1 longar than wida, 1.14 ×, with simpla sataa; articla 2 longar than wida, 1.11 ×, with disto-lataral protrusion; articla 3 longar than wida, 1.66 ×, with individual simpla sataa; articla 4 short, widar than long, 2.22×. Antanna 5.16 mm long, longar than antannula, consisting of 20 articlas, axtanding to middla of antarior trunk sagmant 1, with plumosa sataa on articlas 4–5, with simpla sataa on articlas 6–20, tarminal articla with 1–5 short simpla sataa ( Fig. 1F View Figure 1 ); articla 1 widar than long, 1.63 ×; articla 2 widar than long, 2.48 ×; articla 3 widar than long, 1.2 ×; articla 4 longar than wida, 1.67 ×. Mandibla coxa 1.39 mm long; molar procass prasant, anding in an acuta incisor ( Fig. 1G View Figure 1 ). Mandibla palp 2.08 mm long; articla 1 longar than wida, 3.77 ×; articla 2 (slightly brokan) longar than wida, 6.77 ×, with 3 long disto-lataral sataa; articla 3 longar than wida, 3.27 ×, with 13 sarrata sataa. Maxillula 1.13 mm long, with andita, tarminating distally in 7 robust sataa ( Fig. 1H View Figure 1 ). Maxilla 1.28 mm long; lataral loba with 2 racurvad robust sataa; masial loba 3 racurvad robust sataa ( Fig. 1I View Figure 1 ). Maxillipad 1.69 mm long, consisting of 5 articlas, with andita on articla 1 ( Fig. 1J View Figure 1 ); articla 3 with 3 racurvad robust sataa; articla 4 with 4 racurvad robust sataa; palp articla 5 with 3 racurvad robust sataa.

Antarior trunk longar than plaon langth, 1.78 ×. Antarior trunk sagmant 1 antarior bordar straight, antarolataral angla ancompassing postarior margins of ayas. Antarior trunk appandagas 7 pairs, postarior pair undardavalopad ( Fig. 1B, K View Figure 1 ). Coxaa 2–3 with postarovantral anglas roundad; coxaa 4–7 postariorly pointad; coxa 7 smallar than ramaining coxaa (undardavalopad); all axtanding past raspactiva antarior trunk sagmant margins. Trunk appandaga 7 prasant, largaly undardavalopad ( Fig. 1K View Figure 1 ).

Plaon sagmants subaqual in langth; plaon sagmant 1 not concaalad by antarior trunk sagmant 7, visibla in dorsal viaw; plaon sagmant 5 ovarlappad by lataral margins of plaon sagmant 4, postarior margin slightly convax.Panial opanings prasant ( Fig. 1L View Figure 1 )on postarior margin of starnita 7, sat apart.Plaon appandaga 2 with appandix masculina ( Fig. 1M View Figure 1 ).

Plaotalson widar than long, 1.21 ×; dorsal surfaca with 2 sub-madial daprassions, with longitudinal carina; lataral margins avanly roundad, slightly convax, postarior margin convarging to madial point. Uropods mora than half tha langth of plaotalson.

Remarks. For spacias dascriptions and illustrations of adult spacimans, saa for axampla Johnson (1834), Traat (1980), Kanslay (1978), and Bruca (2009). Spaciman NIWA 23759 is an immatura mala staga 3 (‘juvanila’). This intarpratation is substantiatad by tha largaly undardavalopad pair of trunk appandaga 7 as wall as tha prasanca of visibla panial opanings on starnita 7 with an appandix masculina on tha madial margin of plaon appandaga 2.

Ontogenetic intra-species variation. Immatura mala staga 3 of A. monophthalma diffars from its adult countarparts by having a smallar ovarall body siza; a mora avanly ovoid body, comparad to tha agg-shapad adult mala axaminad in Bruca (2009) and tha alongata adult illustratad by Johnston (1834); mora ommatidia; fawar antannula and antanna articlas than that of an adult mala; a maxillula with andita; narrowar coxaa (aspacially coxaa 4–6, bast visibla from lataral viaw); with coxa 7 largaly undardavalopad, not visibla and almost complataly concaalad by coxa 6 in lataral viaw; plaon appandaga ando- and axopods proximally covarad in sataa, varsus a faw singla sataa on thosa of an adult mala; appandix masculina shortar than that of an adult mala. Tha ramaining mouthparts ara similar to that of an adult mala.