|Checklist of the Collembola: Reproducing schematic habitus images based on original colouration descriptions|
Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium
Reproducing schematic habitus images based on an algorithmic translation of original colouration descriptions.
The generated images are built up in a layered model.
From bottom to top:
Body background colour.
Body pigmentation pattern.
Each level can be built up in (semi)transparant layers.
A standard background colour description is required to be able to compare habitus descriptions of different species.
A colour has 3 parameters: colour(H,S,L)
H: hue or type of colour : 0-360 = visible spectrum
The primary colours are red (h=0), green (h=120) and blue (h=240).
The secondary colours are positioned inbetween two primary colours : red green = yellow (h=60), green blue = cyan (h=180), blue red = magenta (h=300).
Tertiary colours are positioned inbetween a primary colour and a secondary colour : red yellow = orange (h=30), yellow green (h=90), green cyan (h=150), cyan blue (h=210), blue magenta (h=270), magenta red = violet (h=330).
S: saturation or purity or intensity or chroma of the colour : 0-100%
0% = no colour
100 = pure colour
L:: lightness or brightness of the colour : 0-100%
0% = absence of light = black
50% = normal light level
100% = maximum light level = white
Summary : any colour can be described as HSL(H,S,L)
The colours white and black are used to create respectively
a light tint and/or a dark shade of any pure colour.
Mixing black (=HSL(any,0%,0%)) and white (=HSL(any,0%,100%)) results in grey (=HSL(any,0%,50%)).
Mixing black with a pure colour results in a (dark) shade of that colour HSL(H,100%,49-0%).
Mixing white with a pure colour results in a (light) tint of that colour HSL(H,100%,51-100%).
Mixing grey (=black+white) with a pure colour results in a tone of that colour.
Example of tones of colour "blue":
|H = 240°
|100 Maximum light|
|87.5 Very light|
|75 Medium light|
|62.5 Slightly light|
|50 Normal light|
|37.5 Slightly dark|
|25 Medium dark|
|12.5 Very dark|
|0 No light|
1. = having a less intense colouration of yellow : S=25-75%
2. = slightly yellow = slight degree of colouration of yellow : S=25-75%
S=0% = no colouration = grey.
S=100% = maximum colouration = pure colour.
We distinguish 3 levels of -ishness:
dull S = 25%
pale S = 50%
bright S = 75%
greyish blue = blue + less intense grey
blue = HSL(240,100%,50%)
grey = HSL(NA,0%,50%)
greyish = layer with opacity 0.5 of grey
bluish grey = grey + less intense blue
grey = HSL NA,0%,50%
blue = HSL 240,100%,50%
bluish = layer with opacity 0.5 of blue
??? HSL 240,25%,50%
greyish blue = s=75%
bluish grey = s=25% includes bluish white + bluish black
bluish white = s=25% + l=62.5%-87.5%
bluish black = s=25% + l=37.5%-12.5%
whitish blue = l=62.5%-87.5%
blackish blue = l=37.5%-12.5%
whitish grey = s=0% + l=62.5-87.5%
blackish grey = s=0% + l=37.5-12.5%
greyish white = s=0% + l=87.5%
greyish black = s=0% + l=12.5%
= adding another layer of colour with low opacity
The opacity of the white or black layer on top of the colour
controles the level of paleness or darkness of the colour.
"yellowish grey" = grey + white 0.8 + yellow 0.3
"diffuse violet pigment" = pale violet 0.3
"pale yellowish" = yellow + white 0.5
"pale violet brown" = brown + white 0.2 + paleviolet 0.3
"violet blue" =
"yellowish white" =
"dark blue" =
"pale yellow" =
"violet grey" =
"pale bluish violet" =
To be completed.
Yellowish grey + diffuse violet pigment (Fjellberg 2007:178).
Layer 1 = grey = HSL NA,0%,50%
Layer 2 = yellowish = less intense yellow = HSL 60,100%,50% with opacity 0.5
Layer 3 = diffuse violet = HSL 330,100%,50% with opacity 0.2
Pale yellowish + variable violet pigmentation : usually dark lateral band + dorsal spot, these may expand+fuse to cover most larger abdomen (Fjellberg 2007:179).
Sminthurides malmgreni forma principalis Tullberg 1877
Body uniformly violet (Stach 1956:32).
Sminthurides malmgreni forma immaculatus Axelson 1905
Addomen yellow. Dark violet pigment forms only a band ventrolaterally on each side of great abdomen (Stach 1956:31).
Sminthurides malmgreni forma maculatus Agren 1903
Besides ventrolateral band, on dorsum a dark violet spot (Stach 1956:31).
Sminthurides malmgreni forma abruptus Agren 1903
On dorsum two dark violet spots lying one behind the other, the anterior smaller and the posterior elongated; ventrolateral broad dark violet band (Stach 1956:31).
Sminthurides malmgreni forma elegantulus Reuter 1883
Besides ventrolateral band, dorsally on great abdomen more or less longitudinal bands and patches (Stach 1956:32).
Sminthurides malmgreni forma quadrilineatus Agren 1903
On great abdomen four violet longitudinal bands, two ventrolateral and two submedian (Stach 1956:32).
Sminthurides malmgreni forma nigrescens Börner 1901
Darkly pigmented dorsum on which only more or less large spots remain laterally from the pale ground colour (Stach 1956:32).
Sminthurides malmgreni forma palustris Folsom & Mills 1938
Dark pigment weakly developed; only diffuse pigmentation ventrolaterally and dorsally on abdomen (Stach 1956:32).
Sminthurides malmgreni forma dorsomaculatus Janssens & Picard 2018
Only dorsal violet spot. (Janssens 2018:il).
Pale bluish violet (Fjellberg 2007:185).
Violet blue (Fjellberg 2007:181).
Pale yellowish + violet lateral band + dorsal spot, split in 2 bands in less pigmented specimens (Fjellberg 2007:178).
Pale violet brown + 2 darker longitudinal dorsal bands (Fjellberg 2007:181).
Violet grey (Fjellberg 2007:183).
Pale yellow + violet pigment on large abdomen leaving anterior midline + parts of sides unpigmented (Fjellberg 2007:183).
Yellowish white; abdomen darker + crosslike violet figure (Fjellberg 2007:182).
Dark blue (Fjellberg 2007:183).
Violette, avec quelques petites taches claires ā l'avant (Betsch & Massoud 1970:213).
To be completed.