Tridacna elongata var. squamosina Sturany, 1899

Albano, Paolo G., Schnedl, Sara-Maria, Janssen, Ronald & Eschner, Anita, 2019, An illustrated catalogue of Rudolf Sturany's type specimens in the Naturhistorisches Museum Wien, Austria (NHMW): Red Sea bivalves, Zoosystematics and Evolution 95 (2), pp. 557-598 : 557

Tridacna elongata var. squamosina Sturany, 1899 Figure 5

Tridacna elongata squamosina Sturany 1899: 283-284, not figured.

Type locality.

Yemen, Red Sea, Kamaran Isl., ca 15°17'N; 42°37'E, shallow water.

Type material.

Lectotype: NHMW 107075: 2 valves (1 specimen), station 43 designated by Huber and Eschner (2011). Paralectotypes: NHMW 107076: 8 valves (4 specimens), station 12; NHMW 107077: 4 valves (2 specimens), station 10.

Original description.

Die stattliche Reihe der vorliegenden Schalen veranlasst mich, die in der Reeve’schen Monographie abgebildete Tr. compressa als Jugendform der elongata Lm. aufzufassen und ihren Namen einzuziehen, hingegen eine Varietät besonders hervorzuheben, die systematisch zur Tr. squamosa Lm. hinüberführt. Diese mit squamosina nov. var. zu bezeichnende Form liegt von den Localitäten 12, 14 und 43 in mehreren Exemplaren vor und ist durch die hauptsächlich gegen den Unterrand blättrig aufgestellten Querschuppen der Rippen ausgezeichnet.

Translation.

The impressive series of shells induces me to consider the Tridacna compressa depicted in Reeve’s monograph as a young form of T. elongata Lamarck, and to cancel this name, and to highlight a variety that is systematically close to Tr. squamosa Lamarck. This form should be designated as Tridacna squamosina nov. var. and several specimens are present from the localities 12, 14 and 43 and it is distinguished by the foliated transverse scales of the ribs mainly towards the lower margin.

Comments.

Sturany introduced the name Tridacna squamosina for a variety of Tridacna elongata Lamarck, 1819; it has a subspecific rank according to the Art. 45.6.4 of the ICZN. This species had been poorly known for a long time but was recognised as a distinct entity on the basis of a molecular phylogeny with the mitochondrial gene 16s rRNA ( Richter et al. 2008). However, Richter et al. (2008) described this entity with the new name Tridacna costata which was recognised as a junior synonym of T. squamosina by Huber and Eschner (2011).

Figures

Figure 5. Tridacna elongata var. squamosina Sturany, 1899. A-F. Lectotype NHMW 107075: right valve exterior (A) and interior (B), left valve exterior (C) and interior (D), back view (E), front view (F). Scale bar: 2 cm.