ional ▁cet ace ans ▁catch es . ▁ ▁Project s ▁on ▁horses ho e ▁c rab s ▁▁ ▁H ors es ho e ▁c rab s ▁are ▁not ▁real ▁c rab s , ▁but ▁more ▁closely ▁related ▁to ▁sp iders ▁or ▁sc orp ions . ▁The ▁horses ho e ▁c rab s ▁have ▁been ▁sw imming ▁in ▁the ▁Earth ' s ▁waters ▁for ▁ 4 0 0 ▁million ▁years . ▁Although ▁they ▁are ▁not ▁in ▁the ▁end anger ed ▁species ▁list , ▁their ▁numbers ▁are ▁dro pping ▁to ▁be ▁in ▁the ▁ext inction ▁list . ▁ ▁City ▁University ▁of ▁Hong ▁Kong ▁has ▁conducted ▁a ▁study ▁on ▁the ▁horses ho e ▁c rab s ▁in ▁Hong ▁Kong . ▁the ▁result ▁shows ▁that ▁now ad ays ▁only ▁ 1 ▁or ▁ 2 ▁c rab s ▁can ▁be ▁found ▁in ▁every ▁, ▁a ▁decrease ▁of ▁ 9 0 % ▁in ▁four ▁years ▁when ▁compared ▁to ▁ 1 0 ▁to ▁ 2 0 ▁in ▁ 2 0 0 2 . ▁ ▁The ▁biggest ▁threat ▁to ▁the ▁horses ho e ▁c rab s ' ▁population ▁is ▁from ▁poll ution ▁and ▁the ▁development ▁of ▁the ▁city ' s ▁sh or elines , ▁which ▁are ▁destroy ing ▁the ▁ground ▁for ▁the ▁creature ▁to ▁lay ▁eggs ▁and ▁bre ed . ▁ ▁In ▁the ▁light ▁of ▁this , ▁OP CF H K ▁have ▁offered ▁fund ing ▁of ▁ 5 ▁million ▁dollars ▁in ▁ 2 0 0 6 – 2 0 0 7 ▁to ▁save ▁marine ▁animals ▁and ▁horses ho e ▁c rab