Umndeni wama-Rhincodontidae wakhiwa mkhakhawo owodwa kanye nomhlobo munye. Ifesi le imhlobo wesilwani esikhulu kinazo zoke iinlwani eziphilako begodu ubudisi bayo bungaba matani alitjhumi nantathu (20 tons). Kanengi zivame ukubonwa zikhamba ngayinye, kodwana zisuka emhlambini wekhulu lazo. Zinokufudukela eendaweni ezande khulu ngomhlobo weemilo ezibizwa ngama-plankton. Ububanzi bomlomayo bungabalelwa emitheni yinye nahlanu (1,5m) begodu inamazinywana ahlaleleneko amatsikana angaba ma-300-350, nokho ayiwasebenziseli ukudla. Ukubulungeka kwazo kubogaboga khulu begodu akuthabisi. Zimhlobo oqoqoselela ngendeni begodu amadzinyanazo azalwa sele aphila begodu ahlume ngokwaneleko, anjalo nje asuke amasenthimitha amatjhumi amane ukuya kamatjhumi asithandathu wobude. Zinjalo nje zikghona ukuphila iminyaka beyibe likhulu.