Mariana's Hardyhead, Craterocephalus marianae Ivantsoff, Crowley & Allen 1987


Mariana's Hardyhead, Craterocephalus marianae. Source: Neil Armstrong. License: All rights reserved

Summary:
Mariana’s Hardyhead is a small, robust species grouped in the eyresii species complex. This species has a restricted distribution, found only in the Alligator Rivers region of the Northern Territory. Mariana’s Hardyhead has a distinctive dark-edged silver mid-lateral stripe.

Cite this page as:
Vanessa J. Thompson, Craterocephalus marianae in Fishes of Australia, accessed 18 Oct 2018, http://fishesofaustralia.net.au/home/species/1382

Mariana's Hardyhead, Craterocephalus marianae Ivantsoff, Crowley & Allen 1987

More Info


Distribution

Known only from the Mann River to South Aligator River, on the north coast of the Northern Territory. Inhabiting fast-flowing shallow freshwater creeks with sand or gravel bottoms. This species has a high thermal tolerance as the temperatures in pools they inhabit may reach up to 39.5º C. Juveniles form schools while larger individuals are usually solitary or in small groups.

Features

D1 V-VII; D2 I, 5-6; A I, 5-7; P 11-14; GR in 1st lower gill arch 8-10; vertebrae 32-33

Body laterally compressed, relatively slender and elongate; greatest body depth 4.0-4.8 in SL; head length in SL 3.0-3.4; eye diameter in HL 3.0-3.7; dorsum of head above snout convex and sloping towards mouth; mouth small, protrusible, gape restricted by fusion of lips; lips moderately thick; premaxilla longer than in other species of Craterocephalus, just reaching vertical through anterior margin of orbit; upper jaw with fine teeth pointing posteriorly.

Body scales large, ellipsoid to rectangular, scalloped anteriorly; circuli on anterior half of scale; vertical scale rows 27-30; horizontal scale rows 5-6; preopercle with 3 scales; opercle with 4 large scales; scales on dorsum of head rectangular and large.

Two separate dorsal fins; origin of first dorsal just behind origin of ventral fin; origin of second dorsal fin above and just behind origin of anal fin; spines of first dorsal fin weak but not extended or filamentous; caudal fin forked

Size

To 7.5 cm SL.

Colour

Overall yellowish with dusky scale margins dorsally and a dark-edged silver mid-lateral stripe; often with a row of small dark spots below mid-line.

Feeding

Omnivorous benthic feeder consuming algae, micro-crustaceans, aquatic insects and detritus.

Biology

Breeding occurs opportunistically with a peak early in the wet season; spawn in pairs depositing adhesive eggs amongst aquatic vegetation. Eggs with adhesive filaments. Larvae hatch at 5-7 mm TL.

Fisheries

No existing fishery

Conservation

Listed as Data Deficient in the IUCN Red List of Threatened Species.
Not listed under the Australian EPBC act.

Remarks

Has been previously mis-identified as C. marjoriae.

Similar Species

Craterocephalus marianae is most similar to C. helenae but differs in scale counts, the presence of a row of spots below the midlateral scales and a more rounded snout.

Etymology

Generic name Craterocephalus comes from the Greek meaning bowl or basin and head, possibly in reference to the strong head of species in this genus. Species is named marianae in honour of the senior author's daughter Mariana.

Species Citation

Craterocephalus marianae  Ivantsoff, W., Crowley, L.E.L.M. & Allen, G.R. (1987). Descriptions of three new species and one subspecies of freshwater hardyhead (Pisces: Atherinidae: Craterocephalus) from Australia. Rec. West. Aust. Mus. 13(2): 171–188 [179 fig. 4]. Jabiru, Magela Creek, NT [12°41's, 132°55'E].

Author

Vanessa J. Thompson

Mariana's Hardyhead, Craterocephalus marianae Ivantsoff, Crowley & Allen 1987

References


Allen, G.R., Midgley, S.H. & Allen, M. (2002). Field guide to the freshwater fishes of Australia.  Perth : Western Australian Museum 394 pp.

Ivantsoff, W., Crowley, L.E.L.M. & Allen, G.R. (1987). Descriptions of three new species and one subspecies of freshwater hardyhead (Pisces: Atherinidae: Craterocephalus) from Australia. Rec. West. Aust. Mus. 13(2): 171–188

Larson, H.K. & Martin, K.C. (1990). Freshwater Fishes of the Northern Territory. Northern Territory Museum of Arts and Sciences Handbook Series Number 1.  Darwin : Northern Territory Museum of Arts and Sciences 102 pp.

Woodland D.J. & Ward P.J. (1992) Fish Ccommunities in sandy pools of Magela Creek, Alligator Rivers region. Research Report 9. Australian Government Publishing Service Canberra.

World Conservation Monitoring Centre (1996). Craterocephalus marianae. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.3. www.iucnredlist.org

Quick Facts


CAAB Code:37246024

Habitat:freshwater

Max Size:7.5 cm

Native:endemic

Species Image Gallery

Species Maps

CAAB distribution map