Farawa daga gefen shiryayyen nahiyoyi, ana iya cewa ya shiga babban zurfin, halin rashin kusan haske. Yana da yankin wanka, wanda ya hada da nahiyoyin nahiyoyin duniya, sannan yankin mara kyau mara kyau wanda ke da fiye da mita 3.000, da kuma yankin magana, wanda ya saba da ramuka na Mariana.
Wadannan zurfin yankuna suna da talaucin ruwan teku ichthyofauna saboda rashin abinci, ƙarancin iskar oxygen, matsin lamba mai ƙarfi ƙwarai da ƙarancin zafin jiki mai ƙarfi.
A cikin Bahar Rum, raguwar sananne ne musamman, Bayan zurfin mita 1000 kawai nau'ikan 36 ne aka rubuta de peces. Halin da ake ciki na mawuyacin yanayi na abubuwan muhalli ya ta'azzara a cikin wannan tekun ta zurfin zurfin mashigar ruwan Gibraltar, wanda ke hana shigar zurfafan halittu daga tekun Atlantika.
da nau'ikan maganin jijiyoyin jikin mutum da na bathypelagic, tsakanin 200 zuwa 1000 m, suna da siffofin ban mamaki fiye da ƙasa waɗanda suka karkace da yawa daga abin da ya dace da tunanin kifin. Kyakkyawan misali game da wannan yanayin ilimin halittar shine kifin gatari. Mafi yawan de peces A cikin waɗannan zurfin zurfi suna sanye take da gabobin haske ko photophores, waɗanda zasu iya yin aiki duka don ganewa ta musamman kuma don jawo hankalin ganima.
Gabaɗaya, suna da ƙananan girma. Akwai, duk da haka, sanannun keɓaɓɓu, misali, 'sake dubawa glesne'zai iya kaiwa kuma ya zarce ma tsawon mita uku. Hankula mesoplegic iyalai ne, da sauransu, da mytophidsda mai girman kaida gonostomatidsda kaifi da kuma kyautai.
Yawancin waɗannan kifayen suna nuna ƙaura mai mahimmanci a tsaye, kuma motsa dare zuwa matakan epipelagic. Wasu suna zuwa mita 1000 da daddare, ƙaurawar dare a tsaye tsakanin mita 300 zuwa 700 ba ƙa'ida ce a yawancin myctophids.
da jinsin betonic na wannan yanki yawanci suna sama da zurfin 1000 m. Tsakanin zurfin zurfin 2.000 zuwa 3.000, an rage yawan jinsin zuwa bakwai ne kawai a cikin Bahar Rum.