Dysalotus alcocki MacGilchrist 1905


Illustration of Dysalotus alcocki. Source: SAIAB / FishBase. License: All rights reserved

Summary:
A swallower that lacks vomerine teeth, has three to five rows of enlarged, conspicuous prickles on the rear half of the body, and a ventral chin knob at the symphysis of the lower jaw.

Cite this page as:
Bray, D.J. 2017, Dysalotus alcocki in Fishes of Australia, accessed 15 Dec 2017, http://fishesofaustralia.net.au/Home/species/5289

Dysalotus alcocki MacGilchrist 1905

More Info


Distribution

Coral Sea, Australia. Elsewhere, the species is widespread in the Atlantic, Pacific and Indian Oceans, more commonly at low latitudes.
Adults inhabit meso- to bathypelagic waters, while larvae and juveniles usually occur in shallower waters.

Features

First dorsal-fin rays VII (1), VIII (3), IX (4), X (10), XI (2); second dorsal-fin rays ii+23 (1), iv+20 (1), v+20 (1), iv+21 (2), iv+22 (2), iv+23 (2), v+23 (2), vii+21 (1); total rays in second dorsal fin 22 (1), 23 (1), 24 (1), 25 (4), 26 (2), 27 (3), 28 (5), 29 (3); anal-fin rays x+19 (1), iii+23 (1), v+21 (1), vi+21 (3), iv+23 (2), v+23 (1), vi+22 (1); total anal-fin rays 24 (1), 26 (3), 27 (7), 28 (7), 29 (2); pectoral-fin rays 10 (1), 11 (9), 12 (10); pelvic-fin rays I+5 (20); caudal-fin rays ii+6+6+ii (2), ii+6+7+ii (18). Branchiostegal rays 7 (19), 8 (1). Precaudal vertebrae 15 (2), 16 (2); total vertebrae 38 (1), 39 (3), 40 (1). One specimen with 38 total vertebrae listed by Johnson & Cohen (1974). Lateral line complete, total pores 39 (1), 40 (1), 41 (2), 42 (5), 43 (6), 44 (4). Pores in temporal canal 2 (17); supratemporal canal 3 (14); otic canal 1 (9), 2 (5); supraorbital canal 4 (1), 5 (11); epiphyseal branch 2 (9); infraorbital canal 10 (9), 11 (10); preopercular canal 5(1), 6 (19); mandibular canal 6 (18), 7 (1). Prickles present on posterior half of body and caudal peduncle, irregularly distributed in three to four rows dorsal and ventral to lateral line.
Dentittion: Teeth present on premaxilla, dentary, palatine, upper pharyngobranchial and fifth ceratobranchial. Dentigerous areas of premaxilla and dentary illustrated in Fig. 4(a). Premaxillary teeth 75 (1), 80 (1), 81 (1), 84 (1), 90 (1), 95 (1), 99 (1), 100 (1), 101 (1), 102 (1), 104 (1), 106 (1), 107 (1), 109 (1), 117 (1), arranged in two to five rows. Dentary teeth 76 (1), 77 (1), 84 (1), 90 (1), 92 (1), 96 (2), 101 (1), 102 (1), 103 (2), 105 (1), 108 (1), 109 (1), 126 (1), arranged in two to five rows; palatine teeth 5 (1), 6 (1), 8 (4), 9 (3), 10 (2), 11 (2), 12 (2), 13 (1), 14 (1), 16 (1), arranged in single row; vomerine teeth absent (20). Gill rakers tooth-like, present on gill arches individually or in groups of two or three rakers. Rakers on first basibranchial 0 (10), 1 (1), 2 (1), 3 (1), 4 (1); rakers on first ceratobranchial 10 (1), 11 (1), 15 (2), 16 (1), 17 (4), 19 (3), 20 (1), 21 (2), 22 (2), 25 (2), 28 (1); rakers on first epibranchial 6 (1), 8 (1), 11 (3), 12 (2), 13 (4), 14 (5), 16 (3), 17 (1).

Feeding

Adults feed mostly on fishes.

Similar Species

Dysalotus alcocki differs in lacking vomerine teeth, and having three to five rows of emergent prickles above and below the posterior half of the lateral line, vs. vomerine teeth in one to three rows, and a single row of emergent prickles above and below the posterior half of the lateral line (may also have prickles buried in the skin) in Dysalotus oligoscolus.

Author

Bray, D.J. 2017

Dysalotus alcocki MacGilchrist 1905

References


Carpenter, K.E., Smith-Vaniz, W.F., de Bruyne, G. & de Morais, L. 2015. Dysalotus alcocki. The IUCN Red List of Threatened Species 2015: e.T21113900A21914265. http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T21113900A21914265.en. Downloaded on 06 October 2017.

Johnson, R. & Keene, M. 1990. Chiasmodontidae. In: J. Quero, J. Hureau, C. Karrer, A. Post & L. Saldunha (eds) Check-list of the fishes of the eastern tropical Atlantic, CLOFETA, Paris.

Melo, M.R.S. 2016. A review of the genus Dysalotus (Percomorphacea: Chiasmodontidae), with the description of Dysalotus pouliulii sp. nov. Journal of Fish Biology 1-17. Online early DOI: 10.1111/jfb.13194 Abstract

Quick Facts


CAAB Code:37402003

Conservation:IUCN Least Concern

Depth:746-3129 m

Max Size:22.5 cm SL

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