Ke hoʻomaka nei mai ka lihi o ka papa ʻaina, hiki ke ʻōlelo ʻia komo ia i loko o hohonu loa, ʻano e ka nele maoli o ka malamalama. ʻO ia ka ʻāpana bathyal, ʻo ia hoʻi ka pali ʻĀinapuniʻole, a ukali ʻia e ka ʻāpana kai abysmal me nā mika he 3.000, a me ka wahi hadal, kahi maʻamau o nā ʻauwaha Mariana.
Loaʻa kēia mau wahi hohonu i ilihune kai ichthyofauna ma muli o ka nele i ka meaʻai, ka hoʻohaʻahaʻa oxygen haʻahaʻa, nā kaomi kiʻekiʻe loa a me ka mahana haʻahaʻa haʻahaʻa haʻahaʻa loa.
Ma ke Kaiwaenahonua, ʻike nui ʻia ka hōʻemi, ma mua o 1000 mau mika o ka hohonu 36 wale nō ʻano iʻa i ʻōlelo ʻia. Hoʻonui ʻia ke kūlana paʻakikī o nā hanana kaiapuni i kēia kai e ka hohonu pāpaʻu o ka Strait o Gibraltar, ka mea e pale ai i ka hele ʻana o nā ʻano hohonu mai ʻAkelanika.
ka ʻano mesopelagic a me bathypelagic, ma waena o 200 a me 1000 m, he mau a ʻoi paha a ʻano like ʻole o ko lākou ʻano ʻē aʻe i kuhi hewa he nui mai ka manaʻo kūpono o kahi iʻa maʻamau. ʻO kahi laʻana maikaʻi o kēia morphology laha ʻole ka iʻa koi. Hāʻawi ʻia ka hapa nui o nā iʻa i kēia hohonu hohonu me nā ʻāpana māmā a i ʻole nā photophores, i hiki ke lawelawe i nā mea ʻelua no ka ʻike intraspecific a e ʻumeʻume i ka mea hiki ke loaʻa.
Ma ka laulā, liʻiliʻi lākou i ka nui. Eia nō naʻe, loaʻa kekahi mau hiʻohiʻona ʻē aʻe, no ka laʻana, 'ʻoarfish nunui'hiki ke piʻi a ʻoi aku i ʻekolu mau mika ka lōʻihi. ʻO nā ʻohana mesormgic maʻamau, a me nā mea ʻē aʻe, ka mytophidska scrawnyka gonostomatidska ʻoiʻoi a me ka makana.
Hōʻike ka hapa nui o kēia mau iʻa i ka neʻe ʻana o ka pae kiʻekiʻe, a neʻe i ka pō i nā pae epipelagic. Hele kekahi i kahi o 1000 mau mika i ka pō, neʻeneʻe ka neʻe ʻana i ka pō ma waena o 300 a 700 mau mika ma nā myctophids he nui.
ka ʻano betonic Aia kēia wahi ma luna o 1000 m ka hohonu. Ma waena o 2.000 a 3.000 m o ka hohonu ka huina nui o nā laha e hoʻemi ʻia i ʻehiku wale nō ma ke Kaiwaenahonua.
E lilo i mea mua e wehewehe