يَتَصَيَّد (هوَ) بينما (هم) يَتَصَيَّدون والفعل الأصل (صَادَ) والذي يعني to hunt كما قُلتَ and the meaning is: 'Do they hunt on this planet?' It is perhaps a bit difficult to make out the original letters of a verb from the other suffixed letters. However, in order to reduce a verb to its root-letters like صاد You can recall its verb-form (i.e. الأوزان) which also carry a part of the meaning. يَتَصَيَّدون is يتفعَّلون which implies volition, anticipation and gradual progression when the doer is a human being. يَتَصَيَّد has a different shade of meaning than يصطاد as it may be used in a negative sense. For example: إنَّهُ يَتَصَيَّد أخطاءَ الآخرين Whereas, إنَّهُ يصطاد العصافير من حديقة منزله This is only to keep in mind and be logically and sensually aware of while widening your horizons in the Arabic language. There are dozens of books that elaborate on verb-formations, but only practice help you acquire the essence of language. Good luck!

The meaning is "hunt down,catch" The dictionary form is "تَصَيَّدَ" يتصيدون is 3rd person plural imperfect conjugation of تَصَيَّدَ