This species is distinguished from all its congeners, except M.affinis, M.australis, M. glutinosa, M. limosa, M. hubbsi, M. hubbsoides, M. jespersenae, M. knappi, M. kuoi, M. mcmillanae, M. paucidens, M. sotoi, M. martinii, by the following characters: gill pouches 6 pairs and a 2/2 multicusp pattern of teeth; differs from its congeners by number of total cusps 34-40 (vs. 30-32 in M. kuoi, 42-88 in M. mcmillanae, 26 in M. paucidens); prebranchial pores 22-26 (vs. 30-31 M. hubbsoides, 28-37 in M. jespersenae, 30-38 in M. knappi, 28-38 in M. sotoi); trunk pores 58-66 (vs. 68-71 in M. hubbsoides, 52-54 in M. martinii); total pores 91-102 (vs. 111-116 in M. hubbsoides, 107-121 in M. jespersenae); with one single conspicuous nasal-sinus papilla in the mid-dorsal surface of the nasal sinus (vs. two bilaterally symmetrical nasal-sinus papillae in M. jespersenae); colour pattern with its body dark brown with white head (vs. body entirely pigmented, without white head, in M. affinis, M. australis, M. hubbsoides, M. knappi, M. kuoi, M. paucidens); further differs from M. hubbsi by the well-developed ventral finfold, 3-7 mm high (vs. vestigial to low, 1-2 mm high) (Ref. 123790). |