Typhlotanaidae Sieg 1984

Key to Typhlotanaidae species in the Brazilian coast (neuter and female only)

1. Pereopods 4–6 carpus with prickly tubercles..................................................................................................................................................................................................... 2 (Typhlotanais Sars, 1882)

– Pereopods 4–6 carpus without prickly tubercles (with specialized hooks/or variable spines form). 7

2. Pereopods 1–3 coxae without spur................................................................................................... 3

– Pereopods 1–3 coxae with spur.................................................. Typhlotanais ischnochela sp. nov.

3. Pereopods 1–3 ischium with seta shorter than merus; pereopods 4–6 basis without conspicuous spines................................................................................................................................................ 4

– Pereopods 1–3 ischium with long seta reaching distal margin of merus; pereopods 4–6 basis with conspicuous spines.......................................................................... Typhlotanais spinibasis sp. nov.

4. Pleotelson distal margin lacking spines............................................................................................ 5

– Pleotelson distal margin with two strong spines............................... Typhlotanais priscilae sp. nov.

5. Cheliped basis smooth; pereopod-1 coxa with seta shorter than half of basis length...................... 6

– Cheliped basis with ventral grooves; pereopod-1 coxa with long seta, longer than half of basis length............................................................................................... Typhlotanais longiseta sp. nov.

6. Pereopods 2–3 coxae with very long setae reaching half-length of basis; pereopods 4–6 propodus distal setae shorter than dactylus and unguis combined........... Typhlotanais andradeorum sp. nov.

– Pereopods2–3coxae with short setae,less than half of basis;pereopods4–6propodus distal setae longer than dactylus and unguis combined; antenna article-2 globose.. Typhlotanais bolarticulus sp. nov.

7. Pleopods present............................................................................................................................... 8

– Pleopods absent, pleonites with pair of ventral plumose setae.............................................................................................................................. Aremus brasilica Segadilha, Gellert & Błażewicz, 2018

8. Pereopods 4–6 carpus without specialized hooks (with variable spines form)................................ 9

– Pereopods 4–6 carpus with specialized hooks; unguis with trifurcated tip; body more than 10 × L:W................................................................... Hamatipeda prolata Segadilha & Błażewicz, 2019

9. Carapace wider than pereonite-6; pereopods 4–6 merus and carpus with circumplumose spines; dactylus and unguis semi-fused................ Meromonakantha mauri Segadilha & Błażewicz, 2019

– Carapace as wide as pereonite-6; pereopods 2–6 merus and carpus with serrated spines; pereopods 4–6 unguis with bifurcated tip; pereopods 4–6 dactylus not fused with unguis............................................. 10 (Paratyphlotanais Kudinova-Pasternak & Pasternak, 1978)

10. Cheliped carpus with 9–10 dorsal and 7–8 ventral setae; pereopod-1 coxa with spur present....................................................... Paratyphlotanais apletos Segadilha & Błażewicz, 2019

– Cheliped carpus with two dorsal and two ventral setae; pereopod-1 coxa without spur........................................................................................ Paratyphlotanais bessai Segadilha & Błażewicz, 2019