Macrotritopus defilippi Verany, 1851

Roper, Clyde F. E., Gutierrez, A. & Vecchione, M., 2013, Paralarval octopods of the Florida Current, Journal of Natural History 49 (21 - 24), pp. 1281-1304 : 1287

Macrotritopus defilippi Verany, 1851 (Type A and Type B)

Macrotritopus defilippi ( Figures 3 and 4 ) appears to be a complex of two distinct morphological types that share the enlarged ventrolateral arms typical of this genus, both common in our samples: type A with 20 individuals, and type B with 22 individuals. Type A ( Figure 3 ) sizes ranged from 1.4 to 4.2 mm ML. It is characterized by: (a) the arm formula of 3> 2> 1 = 4; (c) with the arm chromatophores in one series (the number of chromatophores ranges from 1 to 3); (d) the dorsal mantle is devoid of chromatophores, and the ventral mantle has seven to eight chromatophores located in the middle area; (e) four chromatophores occur on the funnel, two along each side; (f) eight chromatophores are clustered on the dorsal surface of the head, four on each side of the midline; (g) two chromatophores laterally on the ventral surface of the head. Type B ( Figure 4 ) sizes range from 0.9 to 2.5 mm ML. Paralarvae are characterized by (a) arm formula of 3> 1 = 2 = 4; (c) a single, enlarged chromatophore basally on each arm and two chromatophores in two series distally. Other features are the same as in type A.

Figures

Figure 3. Macrotritopus defilippi Type A paralarval chromatophore patterns and arm sucker development. (A) Chromatophores on dorsal surface of mantle, head and arm pairs I and II; (B) chromatophores on ventral surface of mantle, funnel, head and arm pairs III and IV; (C) oral view of sucker development on Arms I to IV. (Size range examined 1.4–4.2 mm mantle length.)

Figure 4. Macrotritopus defilippi Type B paralarval chromatophore patterns and arm sucker development. (A) Chromatophores on dorsal surface of mantle, head and arm pairs I and II; (B) chromatophores on ventral surface of mantle, funnel, head and arm pairs III and IV; (C) oral view of sucker development on Arms I to IV. (Size range examined 0.9–2.5 mm mantle length.)