, ▁gen etic ▁results ▁indicate ▁that ▁this ▁genus ▁is ▁not ▁closely ▁related ▁with ▁Id i ote uth is ▁but ▁actually ▁closer ▁to ▁Mag note uth is . ▁ ▁Description ▁M ast ig opsis ▁h j ort i ▁is ▁similar ▁to ▁Id i ote uth is ▁cord iform is ▁in ▁that ▁it ▁has ▁large ▁fins , ▁skin ▁t uber cles , ▁no ▁pocket ▁between ▁the ▁brid les ▁and ▁the ▁large ▁div iding , ▁protect ive ▁memb ran es ▁on ▁the ▁tent ac ular ▁clubs ▁but ▁the ▁main ▁difference ▁is ▁that ▁this ▁species ▁has ▁phot op hor es ▁on ▁its ▁eyes . ▁The ▁su ck ers ▁on ▁the ▁tent ac ular ▁club ▁are ▁all ▁of ▁similar ▁size , ▁except ▁for ▁those ▁nearest ▁the ▁tip . ▁The ▁fun nel ▁has ▁a ▁lock ing - app ar atus ▁which ▁has ▁an ▁o val , ▁slightly ▁cur ved ▁de pression ▁and ▁towards ▁the ▁posterior ▁its ▁sides ▁pro tr ude ▁having ▁no ▁cart il agin ous ▁f les hy ▁pro jections . ▁The ▁fins ▁are ▁large ▁and ▁measure ▁around ▁ 9 0 % ▁of ▁the ▁length ▁of ▁the ▁mant le . ▁The ▁mant le , ▁head , ▁fun nel ▁and ▁the ▁ab oral ▁surface ▁of ▁the ▁arms ▁in ▁sub ad ult s ▁are ▁covered ▁in ▁large ▁t uber cles . ▁There ▁are ▁two ▁large ▁circular ▁phot op hor es ▁placed ▁on ▁the ▁lower ▁surface ▁of ▁e y eb all . ▁The ▁maximum ▁mant le ▁length ▁att ained ▁is ▁ 1 0 0   mm . ▁ ▁Distribution ▁M ast