Morphology Data of Eptatretus cryptus
Identification keys
Main Ref. Zintzen, V., C.D. Roberts, L. Shepherd, A.L. Stewart, C.D. Struther, M.J. Anderson, M. McVeagh, M. Noren and B. Fernholm, 2015
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors

Descriptive characteristics of juvenile and adult

Striking features
Body shape lateral eel-like
Cross section
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth
Type of scales

Diagnosis: characterized by the combination of the following characters: 7 pairs of gill pouches, 3/3 multicusps, 12–15 prebranchial slime pores (modally 14), 78–86 total slime pores, slime pores without narrow white rim, preocular length 4.8–5.8% TL, and body colour brown to dark brown; differs from all other congeners except E. caribbeaus, E. menezesi, E. strahani, E. cirrhatus, and E. goliath by having 7 pairs of gill pouches and 3/3 multicusps; Eptatretus caribbeaus, E. menezesi, and E. strahani are not found in New Zealand; differs from E. caribbeaus by the number of anterior unicusps (10–11 versus 11–13), posterior unicusps (8–10 versus 10–11), and body colour (brown to dark brown versus light tan); differs from E. menezesi by the tail slime pores (11–14 versus 14–18), total slime pores (78–86 versus 86–94), and ventral finfold colour (brown versus whitish margin); it differs from E. strahani by having visible (versus absent) eyespots, rounded (versus slit-like) 1st few branchial apertures, vestigial (versus welldeveloped) ventral finfold (0.17–0.64%TL versus 1.12–1.16%TL), rounded (versus angled) ventral caudal fin profile, and shallower tail depth (8.1–10.6%TL versus 10.9–12.7%TL); differentiation from E. cirrhatus by the prebranchial slime pores (12–15, modally 14 versus 15– 18, modally 16), its more robust appearance (body depth 8.9–12.0% TL versus 5.9–11.2% TL, often <8.6% TL), and body colour (brown to dark brown versus dark brown to purple-brown); some, and often most, slime pores of E. cirrhatus have a narrow white rim, whereas slime pores in E. cryptus sp. nov. are the same colour as the rest of the body; care must be taken not to interpret residual slime or internal structure of the slime pore for the presence of a white rim; Eptatretus cryptus differs from E. goliath by the trunk slime pores (46–54 versus 56–60) and total slime pores (78–86 versus 89–95); the following character can also help in dissociating E. cryptus from E. goliath: preocular length (>4.8 versus 3.7–5.2% TL) and prebranchial length (>20.3 versus 18.3–20.9% TL) (Ref. 115309).

Description: meristics: 3/3 multicusp pattern; anterior unicusps, 10 (10–11); posterior unicusps, 9 (8–10); left-side cusps, 25 (24–27); prebranchial pores, 14 (12–15); branchial pores, 7 (6–8); trunk pores, 47 (46–54); tail pores, 13 (11–14); total pores, 81 (78–86); 7 pairs of gill pouches associated with 7 pairs of gill apertures; morphometrics, as percentage of TL: preocular length, 5.2% (4.8–6.0%); prebranchial length, 21.5% (20.3–23.6%); branchial length, 6.8% (6.1–8.1%); trunk length, 54.0% (52.4–56.9%); tail length, 17.6% (15.6– 18.5%); greatest body depth including ventral finfold, 10.0% (8.9–12.0%); greatest body depth excluding ventral finfold, 9.8% (8.5–11.5%); depth at pharyngocutaneous duct, 7.7% (7.4–9.8%); depth at cloaca, 8.4% (7.5–9.2%), tail depth, 9.8% (8.1–10.6%); body subcylindrical, slightly deeper than wide at prebranchial and branchial regions, laterally compressed at trunk and strongly compressed at tail; rostrum bluntly rounded; 2 minute bilaterally symmetrical nasal-sinus papillae in the dorsal surface of the nasal sinus (sometimes not observable); eyespots usually well defined, circular in shape and paler than surrounding skin; 3 pairs of barbels on head, 1st 2 subequal in size, 1.4–1.6% TL (0.9–1.6% TL), 3rd one longer, 1.7% TL (1.5–2.1% TL) and adjacent to oral cavity; ventral finfold small, 1.1 mm (1.0–4.9 mm), its origin difficult to assess but located within anterior 51% (50–59%) of body length, extending to cloaca; no ventrolateral branchial finfolds; caudal finfold rounded, thick, its ventral outline nearly straight, beginning immediately posterior to edge of cloaca, extending around tail to dorsal surface, ending about over cloaca; gill aperture well-spaced and linearly arranged; last branchial duct confluent with pharyngocutaneous duct on left side, forming a larger aperture; posterior tip of dental muscle reaches 5th (3rd to 5th) gill pouches (counting from head), with length 22.8% TL (18.9– 23.9% TL); ventral aorta branches at 7th gill pouch (Ref. 115309).

Colour: body uniformly brown to dark brown, without contrasting narrow white rims around the slime pores; branchial apertures and pharyngocutaneous duct openings white; barbels brown with white tips; some specimens bearing pale to white blotching or healed white scarring (Ref. 115309).

Ease of Identification

Meristic characteristics of Eptatretus cryptus

Lateral Lines Interrupted: No
Scales on lateral line
Pored lateral line scales
Scales in lateral series
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle
Barbels 3
Gill clefts (sharks/rays only)
Gill rakers
on lower limb
on upper limb


Dorsal fin(s)

Fins number
Finlets No. Dorsal   0
Ventral  0
Spines total 0
Soft-rays total 0
Adipose fin

Caudal fin


Anal fin(s)

Fins number
Spines total 0
Soft-rays total 0

Paired fins

Pectoral Attributes  absent
Pelvics Attributes  suppressed/absent
Spines     0
Soft-rays   0
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
Entered by Hennyey, Andrea
Modified by Hennyey, Andrea
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