Feeding Behaviour of Cod (Gadus morhua)

1969 ◽  
Vol 26 (3) ◽  
pp. 583-596 ◽  
Author(s):  
V. M. Brawn

Cod 5–90 cm long in captivity used sight to detect food in midwater. Movement of food stimulated feeding but was not essential when feeding on familiar foods. Adult cod could detect and capture falling food down to 2 mm in diameter. Large pieces of food on the bottom were found by sight but smaller pieces were taken after being detected by taste buds on the trailing barbel and pelvic fin rays. Cod were able to detect odours from many live, intact algae, invertebrates, and fish. Food below gravel or stones was located by smell and uncovered by carrying away gravel in the mouth or by rolling stones aside with the head. Food covered by sand was not found. Some live food was captured in the dark. Cod groups fed more effectively than single cod as food deeply buried was uncovered by several fish digging in the same place; food too large for one fish was pulled apart between fish and feeding behaviour by one fish attracted others to the vicinity of food. Thus shoaling of cod may be advantageous to the species by enabling more food to be obtained from a given area.Larval cod reared from eggs first fed 4 days after hatching. Moving particles were followed by eye movements and captured by swimming forward and snapping if the particles moved in front of the head. Eight days after hatching the cod larvae began to feed on fine stationary particles by removing them from the respiratory water flow.

1988 ◽  
Vol 32 (6) ◽  
pp. 975-975 ◽  
Author(s):  
E. Hinkens ◽  
P. A. Cochran
Keyword(s):  
Fin Rays ◽  

Zootaxa ◽  
2012 ◽  
Vol 3586 (1) ◽  
pp. 329 ◽  
Author(s):  
ZACHARY S. RANDALL ◽  
LAWRENCE M. PAGE

The genus Homalopteroides Fowler 1905 is resurrected and distinguished from the genus Homaloptera van Hasselt 1823based on a combination of characters including a unique mouth morphology, dorsal-fin origin over pelvic fin,≤60 lateral-line scales, and≤30 predorsal scales. Species included in Homalopteroides are H. wassinkii (Bleeker 1853), H. modestus(Vinciguerra 1890), H. rupicola (Prashad & Mukerji 1929), H. smithi (Hora 1932), H. stephensoni (Hora 1932), H. weberi(Hora 1932), H. tweediei (Herre 1940), H. indochinensis (Silas 1953), H. nebulosus (Alfred 1969), H. yuwonoi (Kottelat1998), and possibly H. manipurensis (Arunkumar 1999). Homalopteroides modestus (Vinciguerra 1890) is a poorlyknown species that was originally described from the Meekalan and Meetan rivers of southern Myanmar. It occurs in theSalween, Mae Khlong, and Tenasserim basins, and can be distinguished from all other species of Homalopteroides by thecombination of caudal-fin pattern (black proximal and distal bars, median blotch), 15 pectoral-fin rays, pectoral-fin lengthgreater than head length, 5½–6½ scales above and 5–6 scales below the lateral line (to the pelvic fin), 39–44 total lateral-line pores, no axillary pelvic-fin lobe, pelvic fin not reaching anus, orbital length less than interorbital width in adult, and maxillary barbel reaching to or slightly past the anterior orbital rim.


Zootaxa ◽  
2019 ◽  
Vol 4671 (3) ◽  
pp. 396-406
Author(s):  
RICARDO BRITZKE ◽  
NAÉRCIO A. MENEZES ◽  
MAURO NIRCHIO

Mugil setosus Gilbert 1892 was originally described by Gilbert based on specimens from Clarion Island, in the western and most remote of the Revillagigedo Islands, about 1,000 km off the western Pacific coast of Mexico. Examination of the type of material and recently collected specimens from Ecuador and Peru, resulted in the redescription provided herein. Diagnostic characters of the species were mainly: tip of the pelvic fin reaching beyond the vertical through the base of the third dorsal-fin spine, the pectoral-fin rays with ii+13–14 rays, the anterodorsal tip of second (soft) dorsal fin uniformly dark, and an external row of larger teeth, and more internally a patch of scattered smaller teeth, visible mainly in adults 150 mm SL. The expansion of geographic distribution of Mugil setosus and occurrence of Mugil curema Valenciennes 1836 in the Pacific Ocean are discussed. 


2011 ◽  
Vol 9 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Frank Raynner V Ribeiro ◽  
Carlos Alberto S. de Lucena ◽  
Osvaldo T Oyakawa

Pimelodus multicratifer, a new species, is described from the rio Ribeira de Iguape basin. The new species differs from the other Pimelodus species by the following features: 26 to 30 gill rakers on the first branchial arch; a combination of three to six rows of dark spots regularly or irregularly scattered on the flanks and several small dark spots irregularly scattered on the dorsal surface of head, supraoccipital process, and sometimes on the dorsal and caudal fins; striated lips; maxillary barbels reaching between posterior tip of the pelvic-fin rays and posterior tip of the middle caudal-fin rays.


Zootaxa ◽  
2018 ◽  
Vol 4526 (3) ◽  
pp. 373
Author(s):  
MAKOTO OKAMOTO ◽  
HIROYUKI MOTOMURA

A new species of ptereleotrine dartfish, Navigobius asayake, is described based on four specimens (45.0–52.1 mm in standard length: SL) collected from off the Satsuma Peninsula and Tanegashima island, Kagoshima, southern Japan. It is distinguished from other congeners by the following combination of characters: second dorsal-fin rays I, 18–19; anal-fin rays I, 19; pectoral-fin rays 21–22; gill rakers 5–6 + 13–15; head length 25.1–26.4% SL; eye diameter 8.6–10.0% SL; pelvic-fin length 15.2–16.1% SL; and a well-developed yellow stripe extending from behind upper part of eye to beneath first dorsal fin. 


2021 ◽  
Vol 19 (2) ◽  
Author(s):  
George Mendes Taliaferro Mattox ◽  
Camila da Silva de Souza ◽  
Mônica Toledo-Piza ◽  
Claudio Oliveira

Abstract A new species of miniature fish of the characid genus Priocharax is described from a small lake near the rio Ipixuna, rio Purus drainage, Amazonas State, Brazil. It is distinguished from all congeners except P. pygmaeus by the lower number of teeth on the maxilla and dentary. It differs from P. pygmaeus by the presence of two postcleithra and 22–27 branched anal-fin rays (vs absence and 19–22). The new species is further distinguished from other species of Priocharax by a combination of characters involving the number of pelvic-fin rays and branched anal-fin rays, the number of postcleithra, the shape of postcleithrum 3, and the absence of the claustrum. Molecular evidence based on COI sequences of all valid species of Priocharax also corroborates the validity of this new species.


2021 ◽  
Vol 19 (4) ◽  
Author(s):  
Cárlison Silva-Oliveira ◽  
Rafaela P. Ota ◽  
Flávio C. T. Lima ◽  
Lúcia Rapp Py-Daniel

ABSTRACT A redescription of Bryconops gracilis is provided, a species poorly known for more than a century. Bryconops gracilis differs from all congeners by having the following combination of features: eight branched pelvic-fin rays, 31-36 anal-fin rays, 15-17 predorsal scales arranged in a regular series, two rows of premaxillary teeth, and 53-60 lateral-line scales. The species was often misidentified as B. alburnoides by sharing an overall elongated body shape, caudal fin yellowish in life, and a high number of lateral-line scales. A diagnosis between B. alburnoides and B. gracilis is provided. The holotype of B. gracilis which for many years had whereabouts unknown, was recovered, examined and illustrated by CT-Scan. Additionally, more detailed information about the type locality, morphology, color pattern (including in living specimens), habitat and distribution pattern of species are provided.


Zootaxa ◽  
2009 ◽  
Vol 1977 (1) ◽  
pp. 39-48
Author(s):  
HEOK HEE NG

Parakysis hystriculus, new species, is described from the Lalang River drainage in southern Sumatra. It can be distinguished from congeners in having a combination of branched pelvic-fin rays with anterior branch always shorter than posterior branch, lateral edges of head evenly sloping in dorsal view, anteriormost pair of accessory inner mandibular barbels longer than distance separating bases of left and right barbel, outer mandibular barbel with one accessory barbel, mandibular laterosensory pore between bases of inner and outer mandibular barbels present, margin of lower lip with medial concavity, anal fin rounded, caudal fin with narrow lobes having evenly-tapering posteromedial margins and 10 branched rays without secondary branches.


2013 ◽  
Vol 11 (3) ◽  
pp. 525-536 ◽  
Author(s):  
Fernando R. Carvalho ◽  
Francisco Langeani

Hyphessobrycon uaiso is described from the upper rio Paraná basin, rio Grande drainage, Minas Gerais State. The new species differs from its congeners by the short anal fin with 12-17 branched rays, and dorsal fin with ii,7-8 rays. Besides, it can be distinguished by the presence of i,5-6 pelvic fin rays, and by the coloration of the eyes (in life), slightly blue on the lower half and blackish on the upper half. New records of Hyphessobryconare recognized for the upper rio Paraná basin: H. eilyos Lima & Moreira, H. guarani Mahnert & Géry, and H. herbertaxelrodi Géry. The knowledge status about the ichthyofauna from the upper rio Paraná basin and comments about the type material of some species of Hyphessobrycon are briefly discussed.


1983 ◽  
Vol 10 (1) ◽  
pp. 77 ◽  
Author(s):  
CN Johnson ◽  
KA Johnson

The behaviour was observed, in captivity, of the bilby Macrotis lagotis, a fossorial bandicoot of central Australia. Most of the observations were made at night, but some were of below-ground behaviour during the daylight hours. Bilbies proved to be relatively passive in comparison with other bandicoots, and a rigid dominance hierarchy amongst males was maintained without destructive fighting. Dominant males chased subordinate males out of and away from burrows and the alpha male maintained priority of access to all the well used burrows in the enclosure. Males scent-marked around burrows; the dominant male usually marked over scents left by other bilbies. Males shared burrows freely with females, and copulation appears to take place down burrows. Information is also given on female-female and mother-young behaviour, and some suggestions are made concerning the social structure of wild bilbies. Activity cycles, feeding behaviour, etc. are described.


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