Protomelas sp. 'oxyrhynchus mix' Thumbi West Island
Genus:
Protomelas
Biotope:
Sheltered shallow bays with muddy sediment covering sand and rocks;
vegetated areas with Vallisneria spiralis beds (to about 6 m depth),
also non-vegetated shallow intermediate habitats.
Geographic distribution:
Apparently limited to the southern part of Lake Malawi:
Maleri Island, Mumbo Island, and Thumbi West Island.
Typical adult size:
Largest observed male about 20 cm total length;
most females and non-breeding males 14–18 cm total length.
Sexual dimorphism:
Males in breeding coloration observed rarely;
no clear structural differences reported.
Overall body shape resembles Hemitilapia oxyrhynchus
but pigmentation differs markedly.
Diet:
Frequently joins foraging groups of Hemitilapia oxyrhynchus
but feeds differently by ramming its head into the substrate in a vertical,
head-down position to extract prey.
Likely feeds on invertebrates such as insect larvae
(possibly dragonfly larvae among plant roots).
Thick lips probably cushion impact with the bottom.
Breeding:
Poorly known.
A single male in breeding coloration observed;
not territorial at the time and no females nearby.
Aggression:
No clear territorial behavior observed;
appears non-aggressive while foraging.
Special notes:
Characterized by a melanin pattern with the midlateral stripe
broken into three large elongate blotches and a second interrupted
dorsolateral line, unlike the three large flank spots of
Hemitilapia oxyrhynchus.
Often associates with schools of that species,
possibly for protection against predators.
May be conspecific with a form referred to as
Fossorochromis sp. ‘oblique teeth’.
Rare and potentially vulnerable due to its shallow-water habitat.
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