ak , ▁is ▁relatively ▁short , ▁on ▁females ▁in ▁particular ▁bare ly ▁pro tr ud ing ▁beyond ▁the ▁length ▁of ▁the ▁upper ▁mand ible . ▁The ▁males ▁of ▁some ▁species ▁( e . g ., ▁N . ▁e br ard ti i ) ▁have ▁short , ▁straight ▁be aks , ▁but ▁those ▁of ▁others ▁( e . g ., ▁N . ▁li emi ) ▁have ▁short ▁be aks ▁that ▁curve ▁down wards ▁forming ▁a ▁shape ▁often ▁compared ▁to ▁a ▁go ate e ▁be ard ▁by ▁aqu ar ists . ▁ ▁Nom or ham ph us ▁feed ▁extens ively ▁on ▁small ▁insect s , ▁either ▁in ▁the ▁form ▁of ▁aqu atic ▁lar va e ▁or ▁as ▁flying ▁insect s ▁that ▁have ▁fallen ▁onto ▁the ▁surface ▁of ▁the ▁water . ▁They ▁are ▁important ▁pred ators ▁on ▁insect s ▁such ▁as ▁mos qu ito es , ▁so ▁play ▁a ▁role ▁in ▁cont rolling ▁mal aria . ▁Nom or ham ph us ▁are ▁too ▁small ▁to ▁be ▁of ▁value ▁as ▁food , ▁but ▁they ▁do ▁have ▁some ▁value ▁as ▁aqu arium ▁fish . ▁ ▁Re production ▁ ▁Nom or ham ph us ▁species ▁are ▁live b ear ing ▁fish ▁that ▁pract ise ▁internal ▁fert il isation . ▁The ▁male ▁is ▁equ ipped ▁with ▁a ▁g on op od ium - like ▁anal ▁fin ▁known ▁as ▁a ▁g on op od ium ▁that ▁del ivers ▁s perm ▁into ▁the ▁female . ▁The ▁gest ation ▁period ▁is ▁about ▁six ▁weeks . ▁The ▁exact ▁mode ▁of ▁reprodu ction ▁ranges ▁from