Frost, 1943



Citation


Frost, W.E. (1943) The natural history of the Minnow (Phoxinus phoxinus). Journal of Animal Ecology, pp. 139-162

Associated characteristics


Species Development state Trait Primary Data Secondary Data
Phoxinus phoxinus Spawning conditions Mating system The whole mass of minnows, consisting of many males and a few females, in their bright spawning livery, was in a constant state of activity, swimming, twisting and turning in the current, occsionally some of the fish left it for quiter water at the side of the stream, where they disappeared under fist-sized stones. Presumably oviposition occurred then No category
Phoxinus phoxinus Spawning conditions Nycthemeral period of oviposition Observation of spawning were made at about 4.30 p.m. No category
Phoxinus phoxinus Spawning conditions Spawning site preparation Lay their eggs Susbtrate chooser
Phoxinus phoxinus Spawning conditions Spawning temperature Temperature of 58°F, i.e. 14.5°C 58.0 °C
Phoxinus phoxinus Spawning conditions Spawning water type Running waters No category
Phoxinus phoxinus Spawning conditions Spawning depth The minnows, which were in great numbers were in gravelly, fairly swiftly flowing shallows at the side of the stream No data
Phoxinus phoxinus Male Male sexual dimorphism In the male the pectoral fin is broad and rounded, i.e. fan shaped, whereas in the female it is narrow and weakly rounded. Also observed that the first eight fin rays of the pectoral fin thickened in the male and not in the female, a character which first appears in sexually ripe individuals and remains for the rest of life. Windermere fish sowed this sexual dimorphic character well at breeding period, but outside this period it was a little less obvious, no thickening of the fin rays was seen in immature in fish. On the top of the head were a number of milk-white spinose tubercule. The female had much the same colouring of back and sides as the male, the metallic sheen of the sides being perhaps more golden and less green than the male. The head opercules were also present although, in some specimens, much less bodly developed. The breeding coloration in the male is weakly suggested as early as mid-March, but neither male nor female have head tubercles at this time. in both sexes the tubercles are lost after spawning and a tiny hole on the head marks their place Present
Phoxinus phoxinus Egg Egg adhesiveness Egg-masses were found attached to the undersite of the stones Non-Adhesive
Phoxinus phoxinus Egg Incubation time 4-5 days 4.5 days
Phoxinus phoxinus Female Resting period Very little growth takes place through the summer months No data
Phoxinus phoxinus Female Onset of oogenesis During late September and early October there is a considerable increase to about nine times the original volume in case of the ovary and bout three times in the cases of the testes. The volume thus attained remains fairly consistent throughout the winter ['March', 'January', 'September', 'February', 'October']
Phoxinus phoxinus Egg Egg size after water-hardening Newly deposited eggs are 1.5-1.8 mm 1.65 mm
Phoxinus phoxinus Female Intensifying oogenesis activity A final increase takes place in the following spring ['April', 'May', 'June']
Phoxinus phoxinus Spawning conditions Spawning migration period At spawning time the mature lake minnows migrate in large numbers up the inflowing streams, but apart from this no other mass movement has been observed No data
Phoxinus phoxinus Egg Oocyte diameter The egg when just ready for extrusion measures about 1.3-1.4 mm in diameter 1.35 mm
Phoxinus phoxinus Female Absolute fecundity In two-year-old specimens of 42-50 mm. Long there were from 105 to 200 eggs per fish, minnows of the same age but of 51-60 mm. Contained from 180 to 330 eggs, and three-year-old fish of 61-70 mm. Had from 293 to 550 ova to the fish 46.0 thousand eggs
Phoxinus phoxinus Spawning conditions Spawning season The breeding season extends from May to July ['May', 'July']
Phoxinus phoxinus Larvae Full yolk-sac resorption The yolk sac had disappeared by the time the 'pin' minnows were 13-14 days old, they were then 8.0 mm long 13.5 °C * day
Phoxinus phoxinus Female Length at sexual maturity The majority of minnows of over 42 mm, that is, of more than one year old, were sexually mature, although there were some indivudals, males and females, of about 41-45 mm long and in their second year of life which were immature 43.0 cm
Phoxinus phoxinus Male Length at sexual maturity The majority of minnows of over 42 mm, that is, of more than one year old, were sexually mature, although there were some indivudals, males and females, of about 41-45 mm long and in their second year of life which were immature 43.0 cm
Phoxinus phoxinus Larvae Initial larval size Newly emerged fry ranged from 4.2-5.0 4.6 mm
Phoxinus phoxinus Larvae Larvae behaviour From birth they were most active Demersal
Phoxinus phoxinus Spawning conditions Spawning release The condition of spent fish in Windermere, particulalryl of females captured in late May, indicates that all the eggs are shed at one time, and thus long-drawn-out breeding time is not due to the same individuals shedding their eggs and sperm during a protracted period but to a population composed of fish, which mature at different times from may to July No category