Studies on scale regeneration in the Common goby, Pomatoschistus microps (Pisces)

Abstract

With 5 plates and 8 figures in the text)The longevity of original scales and the process and consequences of scale regeneration in the euryhaline Common goby, Pomutoschistus microps (Kreryer), has been studied by monthly sampling of two populations. Scale regeneration comprises four stages: formation of a new growth centre, a regenerated area in the form of a wide central irregular area lacking concentric circuli: formation of short and widely spaced circuli at the outermost region of the regenerated area: a check in regenerated scale growth on reaching the size of the original scales: and the cornmencement of normal growth similar to that of the surrounding original scales. Growth of regenerated scales within 30 days was not sufficient to attain the same size of the original ones. The average percentage of regenerated scales in successive months during the life span of P. microps is about 20 % in immature fish and sharply increases up to about 60% of the total scales during the breeding season. The correlation between sharp increases in regenerated scales and the breeding season is also confirmed on examining scales from two other gobioid species, Gobiuspaganellrcs and Gobius cobitis. It is suggested that the loss of a large number of scales may result in the check in body growth during the breeding season.

Scale calcification in the goldfish in vitro: histological and quantitative analysis

“…They contain a putative calcification-inducing enzyme, alkaline phosphatase, and are generally accepted as calcification-inducing structures in various calcified tissues in mammals [20][21][22][23]. In previous studies of regenerating scales, some researchers have observed matrix-vesicle-like structures with hydroxyapatite-like crystals in the scale marginal area, where calcification initiates [2,7,[16][17][18]. However, a mineral deposit in the external layer independent of such structures has also been observed in scales.…”

“…It was also observed that calcification of these scales could proceed in physiological saline only in their external layer, as observed in the control regenerating scales in vivo. Moreover, electron-dense, spindle-shaped particles, which morphologically resembled mineral deposits present in fish scales [2,7,[16][17][18], grew in an electron-dense substance both in the regenerated scales from control fish and in the in vitro incubated scales from CaDPD fish, although the amount of the substance was smaller in the latter. These findings suggest that the mechanisms of calcification induced in the CaDPD scales in vitro and control scales in vivo are comparable, and thus, the CaDPD scale is a good model with which to study the mechanism underlying the early calcification of teleost scales.…”

Chemical archives in fishes beyond otoliths: A review on the use of other body parts as chronological recorders of microchemical constituents for expanding interpretations of environmental, ecological, and life‐history changes

“…Although different morphologies exist, the highly derived elasmoid scale is the most common in modern fish species (Sire and Akimenko ). Elasmoid scales consist of two distinct layers: an osseous upper layer and an underlying proteinaceous basal layer (Fouda ). The osseous layer is highly calcified and contains collagen fibrils mixed with needle‐shaped crystals of hydroxyapatite (Schönbörner et al ; Sauer and Watabe ).…”

“…Even non‐regenerated scales cannot reliably describe early life history, as most larval teleosts lack scales (Sire and Akimenko ). Although regenerated scales can be identified by an absence of circuli and avoided (Fouda ), non‐regenerated scales may not always be available for analysis (Wells et al ). Regenerated scales may be useful, however, in interpreting microchemistry over a recent, short timespan if the age of regenerated material is known (Hammond and Savage ).…”