Ceradocus sheardi Shoemaker, 1948

Krapp-Schickel, Traudl & Vader, Wim, 2009, On some Maerid genera (Crustacea, Amphipoda, Maeridae) collected by the Hourglass Cruises (Florida). Part 1: Genera Anamaera, Ceradocus, Clessidra gen. nov., Jerbarnia, Maera, Meximaera, with a key to world Ceradocus, Journal of Natural History 43 (33 - 34), pp. 2057-2086 : 2065-2071

Ceradocus sheardi Shoemaker, 1948

( Figures 3 , 4 )

Ceradocus sheardi Shoemaker, 1948: 7–9 , fig. 2; Thomas, 1993:43, fig. 56.

Type locality

Cuba.

1. Length

0:> 5 mm

1: ≤ 5 mm

2. A1 acc. flagellum

0: ≤ 3 arts

1: 4–10 arts

2:> 10 arts

3. Mdb palp art 3:2

0: art 3 shorter than half of art2

1: art 3 half of art2

4. Gn1 ratio propodus: carpus

0: propodus <carpus

1: subequal

2: propodus> carpus

5. Gn2 asymmetrical

0: yes

1: no

6. Gn 2 male larger palm

0: transverse or nearly transverse

1: oblique

7. Gn 2 male larger: propodus ratio length: breadth 0: <1.5

1: 1.5–1.8

2:> 1.8

8. Gn 2 male larger: palm incision(s)

0: present near corner

1: only shallow near corner

2: present medium

3: with broad molar-like hump(s)

4: present near dactylus insert

5: many

6: absent

9. P7 basis ratio length: breadth

0: <1.8

1: ≥ 1.8

10. Ep1 post. margin posteroventral*

0: serrated or uneven toothwaves

1: smooth

11. Ep1 inferior margin*

0: serrated or few incisions

1: smooth

12. Ep2 posterior margin posteroventrally*

0: serrated or toothwaves

1: smooth

13. Ep2 inferior (ventral) margin*

0: serrated or few incisions

1: smooth

(Continued)

14. Ep3 posterior margin posteroventrally*

0: serrated

1: smooth

15. Ep3 inferior margin*

0: serrated or few incisions

1: smooth

16. Metasome segment 1 posterior margin dorsally

0: serrated or at least one small tooth

1: smooth

17. Metasome segment 2 posterior margin dorsally

0: medial tooth large

1: medial tooth small

2: medial gap, lateral teeth

3: smooth

18. Metasome segment 3 posterior margin dorsally

0: normally rounded

1: produced

19. Us1,2 dorsally

0: smooth

1: dentate

20. U3 ratio rami: peduncle

0: <2.0

1: 2.0–2.5

2:> 2.5

21. U3 ratio external ramus ratio length: breadth

0: <4

1: 4–4.5

2:> 4.5

22. Telson lateral fine setae

0: present

1: absent

23. T subdistal robust setae

0: one, long

1: two or three, long

2: many

3: none

4: only short ones

24. Geographical distribution of type species

0: Atlantic

1: Pacific

2: New Zealand / Australia

3: South Africa / Madagascar /Mascarene Islands

4: Mediterranean

*Remarks on epimeral plates: authors have a

different opinion about the posterodistal corner of

the epimeral plates; we agree with Jerry Barnard

defining the corner as the end of the ridge, not the

largest tooth.

Material examined

FSBC I 44583 : 1; 18 m; dredge; 1 July 1967; 27°37′ N, 83°07′ W . FSBC I 44751 : 14 specimems; 55 m; dredge; 12 May 1967; 27°37′ N, 83°58′ W . FSBC I 44753 (MSV): 3 specimens; 18 m; dredge; 5 October 1967; 27°37′ N, 83°07′ W . FSBC I 44807 : 1; 73 m; dredge; 13 June 1966; 26°24′ N 83°43′ W . FSBC I 44808 : 7 adults and juveniles 4–7 mm; 55 m; dredge; 13 October 1966; 26°24′ N, 83°22′ W . FSBC I 44810 : 7 (5 MSV); 55 m; dredge; 16 February 1967; 26°24′ N, 83°22′ W . FSBC I 44812 : 1 slide; 4 specimens; 73 m; 20 foot (6 m) flat trynet; 13 October 1966; 26°24′ N, 83°43′ W . FSBC I 44813 : 5; 55 m; dredge; 7 June 1967; 26°24′ N, 83°22′ W . FSBC I 44814 : 1; 55 m; dredge; 21 May 1967; 27°37′ N, 83°58′ W . FSBC I 44815 : 1; 37 m; 20 foot (6 m) balloon; 7 August 1967; 26°24′ N, 82°58′W . FSBC I 44816 : 1 adult 7 mm, 1 juvenile 4 mm; 55 m; 20 foot (6 m) flat trynet; 15 February 1966; 26°24′ N, 83°22′ W . FSBC I 44819 : 7 specimens alcohol, 1 slide; 55 m; dredge; 12 October 1967; 26°24′ N, 83°22′ W . FSBC I 44822 : 11 adults 5–8 mm; 37 m; dredge; 5 July 1967; 26°24′ N, 82°58′ W . FSBC I 44823 : 1; 37 m; dredge; 1 August 1966; 27°37′ N, 83°28′ W . FSBC I 44824 : 1 adult 7 mm; 55 m; dredge; 12 September 1967; 27°37′ N, 83°28′ W . FSBC I 44827 : 1; 55 m; 20 foot (6 m) flat trynet; 12 October 1967; 26°24′ N, 83°22′ W . FSBC I 44828 : 2; 73 m; 20 foot (6 m) flat trynet; 5 September 1967; 26°24′ N, 83°43′ W . FSBC I 44835 : 4; 37 m; dredge; 20 May 1967; 27°37′ N, 83°28′ W . FSBC I 44837 : 47; 18 m; dredge; 2 November 1967; 27°37′ N, 83°07′ W . FSBC I 44838 : 3; 73 m; dredge; 2 August 1967; 27°37′ N, 84°13′ W . FSBC I 44843 : 4; 37 m; 20 foot (6 m) balloon trynet; 31 August 1967; 27°37′ N, 83°28′ W . FSBC I 44849 : 1 slide; 55 m; dredge; 21 November 1967; 27°37′ N, 83°58′ W . FSBC I 44850 : 1; 37 m; dredge; 2 May 1966; 27°37′ N, 83°28′ W . FSBC I 44851 : 1 adult damaged; 37 m; 20 foot (6 m) balloon trynet; 5 August 1966; 26°24′ N, 82°58′ W . FSBC I 44856 : 14 adults 6–8 mm; 18 m; dredge; 14 November 1967; 26°24′ N, 82°28′ W . FSBC I 44858 : 1; 37 m; dredge; 2 November 1967; 27°37′ N, 83°28′ W . FSBC I 44861 : 19; 55 m; dredge; 5 September 1967; 26°24′ N, 83°22′ W . FSBC I 44866 : 38 specimens, 1 slide; 55 m; dredge; 5 September 1966; 26°24′ N, 83°22′ W . FSBC I 44875 : 5; 55 m; 20 foot (6 m) balloon trynet; 8 August 1967; 26°24′ N, 83°22′ W . FSBC I 44876 : 1; 55 m; 20 foot balloon trynet; 13 November 1965; 26°24′ N, 83°22′ W . FSBC I 44877 : 1; 55 m; dredge; 6 August 1966; 26°24′ N, 83°22′ W . FSBC I 44878 : 1 adult 7 mm; 37 m; dredge; 11 May 1967; 27°37′ N, 83°28′ W . FSBC I 44879 : 1; 37 m; dredge; 6 January 1967; 27°37′ N, 83°28′ W . FSBC I 44880 : 4 adults 6–8 mm; 55 m; 20 foot (6 m) balloon trynet; 6 July 1967; 26°24′ N, 83°22′ W . FSBC I 44881 : 1 adult 5.5 mm; 73 m; dredge; 6 July 1967; 26°24′ N, 83°43′ W . FSBC I 44882 : 5; 55 m; dredge; 8 April 1967; 26°24′ N, 83°22′ W . FSBC I 44883 : 6; 55 m; 20 foot (6 m) balloon trynet; 12 October 1967; 26°24′ N, 83°22′ W . FSBC I 44884 : 1 male 9 mm slide; 55 m; dredge; 7 December 1966; 26°24′ N, 83°22′ W . FSBC I 44885 : 1 adult, 1 juvenile; 18 m; dredge; 31 August 1967; 27°37′ N, 83°07′ W . FSBC I 45622 : 3; 37 m; 20 foot (6 m) balloon trynet; 21 November 1967; 27°37′ N, 83°28′ W . FSBC I 45659 : 5; 55 m; dredge; 15 November 1967; 26°24′ N, 83°22′ W .

Length

9–16 mm.

Features for regional diagnosis

Gn2 not sexually dimorphic, not asymmetrical, palmar margin sinuous, without processes. P7 basis with posteroventral angle rectangular, not projecting into acute lobe. Pleon segments with strong teeth and serrations. Ep1–3 serrated. Us segments 1,2 with teeth. T lobes acutely ending, with strong subapical robust seta (and small additional ones).

Distribution

Atlantic Ocean: Biscayne Bay to Dry Tortugas; Belize, Yucatan, Mexico ( Shoemaker 1948; Thomas 1993; LeCroy 2000); Cuba ( Shoemaker 1948; Ortiz 1974); Puerto Rico ( LeCroy 2000).

Ecology

Rubble zone, lagoon, forereef, 1–2 m: under rocks on sandy bottoms ( Thomas, 1993); down to 52 m ( Thomas, 1993). Here down to 73 m.

Colour

Pure transparent white; U1,2 rami faint salmon pink; eyes dark red, divisions white [Shoemaker’s unpublished colour notes based on live material from Dry Tortugas (fide LeCroy 2000)]; ivory ( Thomas 1993).

Figures

Figure 3. Ceradocus sheardi Shoemaker: 1 male 9 mm, FSBC I 44884. Mdp, mandible palp; Mx1, maxilla 1; Mx2, maxilla 2; LL, lower lip; Gn1, gnathopod 1; Gn2, gnathopod 2.

Figure 4. Ceradocus sheardi Shoemaker: 1 male 9 mm, FSBC I 44884. P7, peraeopod 7; Ep1–3, epimeral plates 1–3; Us1, Us2, urosome segment 1,2; U1–3, uropod 1–3; underneath enlargement of tips of U1; T, telson.