Mariana's Hardyhead, Craterocephalus marianae Ivantsoff, Crowley & Allen 1987
Mariana's Hardyhead, Craterocephalus marianae. Source: Neil Armstrong. License: All rights reserved
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