Examining the highlighted area of your specimen, click on the image below which most closely resembles your specimen. Second basal segment of right 5th leg with small hook, which only slightly extends beyond its segment Second basal segment of right 5th leg with hook long as first exopod   Taxonomy Phylum Arthropoda Subphylum Crustacea Class Maxillopoda Subclass Copepoda Order Calanoida Family Diaptomidae