Morphology Data of Maylandia xanthos
Identification keys
Abnormalities
Main Ref. Ciccotto, P.J., A. Konings and J.R. Stauffer Jr., 2011
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors
Remarks

Descriptive characteristics of juvenile and adult

Striking features
Body shape lateral fusiform / normal
Cross section
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth
Type of scales
Diagnosis

Diagnosis: A moderately-sloped head and bicuspid teeth in the outer row of the jaws place this species in Maylandia (Ref. 86409). The brown and blue/gray alternating lateral bars in conjunction with the yellow dorsal and dark anal fin of breeding males distinguish M. xanthos from males of all other members of Maylandia (Ref. 86409). Female M. xanthos are yellow/brown, usually more yellow than females of any other member of the Aurora group, but not all female M. xanthos can be distinguished according to the colour pattern; Maylandia xanthos is further distinguished from M. aurora males from the Mbweca and Tumbi Point populations that are similar but lack dark pigment in the anal fin, and from the neighboring M. glaucos by the lower jaw length, which is longer in M. xanthos, 34.6–36.7% of head length, than in M. aurora, 28.4–33.5% of head length, and in M. glaucos, 28.8–32.8% of head length (Ref. 86409).

Description: Dorsal snout profile slightly concave to straight; mouth cleft at slightly downward angle; jaws isognathous; teeth on dentary in 2 or 3 rows, on premaxilla in 2 or 3 rows; outer row teeth typically bicuspid anteriorly and unicuspid posteriorly, inner rows tricuspid, innermost row unicuspid; lower pharyngeal jaw with numerous slender teeth with teeth in posterior row slightly larger; portion of upper dental arcade normally visible in closed mouth; tips of teeth in premaxilla and dentary in V-shaped line with anteriormost in upper and lower jaw furthest apart and not touching in closed mouth (Ref. 86409). Lateral scales ctenoid (Ref. 86409).

Colouration: Lateral body colouration of breeding male blue/gray with 6 or 7 brown bars below dorsal fin, yellow ventrally, yellow caudal peduncle with flecks of blue; head gray with 2 blue/gray interorbital bars; ventral third of operculum yellow with gray opercular spot; gular region yellow; dorsal fin yellow with blue lappets; caudal-fin rays yellow with blue membranes; anal fin dark gray/brown with light blue distal edge and 4 orange ocelli; leading edge of pelvic fin white, first ray brown, remainder yellow; pectoral fin clear (Ref. 86409). Female yellow/brown laterally with 5 faint brown bars, yellow breast, and white belly; head orange/brown; gular region yellow; gray/black opercular spot; dorsal fin yellow/brown with orange lappets; caudal-fin rays orange with brown membrane; anal fin orange with 1-4 small yellow ocelli; pelvic fin orange; pectoral fin clear (Ref. 86409).

Ease of Identification

Meristic characteristics of Maylandia xanthos

Lateral Lines Interrupted: No
Scales on lateral line 29 - 32
Pored lateral line scales
Scales in lateral series
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle
Barbels
Gill clefts (sharks/rays only)
Gill rakers
on lower limb 11 - 13
on upper limb 2 - 3
total
Vertebrae
preanal
total

Fins

Dorsal fin(s)

Attributes no striking attributes
Fins number 1
Finlets No. Dorsal   
Ventral  
Spines total 17 - 18
Soft-rays total 8 - 10
Adipose fin absent

Caudal fin

Attributes more or less truncate

Anal fin(s)

Fins number 1
Spines total 3 - 3
Soft-rays total 8 - 9

Paired fins

Pectoral Attributes  more or less normal
Spines     
Soft-rays   13 - 14
Pelvics Attributes  more or less normal
Position    thoracic  behind origin of D1
Spines     
Soft-rays   5 - 5
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
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