Spontaneous melanotic lesions in axillary seabream, Pagellus acarne (Risso)

Area of Science:

• Ichthyology
• Marine Biology
• Veterinary Pathology

Background:

• Melanotic lesions in fish can indicate environmental stress or disease.
• Axillary seabream (Pagellus acarne) are a relevant species for monitoring coastal ecosystem health.

Purpose of the Study:

• To characterize the macroscopic and microscopic features of spontaneous melanotic lesions in Pagellus acarne.
• To differentiate between proliferative and neoplastic melanophore lesions in fish skin.

Main Methods:

• Macroscopic examination of external lesions on fish skin, fins, lips, and conjunctiva.
• Histological analysis of skin nodules and pigmented spots to identify cell types and tissue infiltration.
• Microscopic evaluation of melanophore distribution, melanin concentration, and cellular morphology.

Main Results:

• Identified sessile hyperpigmented spots and nodular lesions on the head, lips, fins, and conjunctiva of Pagellus acarne.
• Histology confirmed spots as proliferative melanophore lesions and nodules as neoplastic melanophoromas.
• Melanophores exhibited high melanin concentration, moderate pleomorphism, and dermal infiltration without muscle invasion.

Conclusions:

• The study characterizes spontaneous melanotic lesions in Pagellus acarne as proliferative and neoplastic melanophoromas.
• These findings contribute to understanding skin pathologies in marine fish populations.
• Further research is needed to determine the etiology and implications of these lesions.