Check-list of chromosome numbers of the family Hygromiidae (Gastropoda: Stylommatophora) with new data on Circassina frutis

Nino Gabroshvili,Levan Mumladze,Nino Chakvetadze,Nana Bakhtadze

doi:10.3897/travaux.64.e69707

Abstract

Chromosome number data on the Hygromiidae (Gastropoda: Stylommatophora) are summarized and reviewed briefly in the context of the phylogeny of the family. In hygromiids, the haploid chromosome numbers range from 21 to 26. It is supposed that n = 21 is the ancestral chromosome number in the family. The modal haploid number for Hygromiidae is 23. Description of karyotype in terms of chromosome number and morphology of hygromiid land snail Circassina frutis is provided for the first time. The diploid chromosome number of this species is 2n = 46. The karyotype is symmetric and consists of 21 pairs of metacentric and 2 pairs of submetacentric chromosomes. The karyotype formula is as follows: 2n = 42m + 4sm (n = 21m + 2sm). The fundamental number (FN) is 92. Chromosomes range in length from 2.53 &mu;m for the smallest pair to 6.00 &mu;m for the largest pair. The total length of chromosomes in diploid complement (TCL) is 170.40 &plusmn; 3.22 &mu;m.

Highlights

The family Hygromiidae Tryon, 1866 is a highly diverse group of terrestrial pulmonate gastropod mollusks
The diploid set (2n) of Circassina frutis consists of 46 chromosomes
Observations on the karyotype and chromosome measurements show that all chromosomes are two-armed and monocentric with a median or submedian position of centromeres (Figs 1–3 and Table 1)

Summary

Introduction

The family Hygromiidae Tryon, 1866 is a highly diverse group of terrestrial pulmonate gastropod mollusks Representatives of this stylommatophoran family are distributed in the Palaearctic from the Macaronesian Islands in the west to the Russian Far East in Copyright Bakhtadze, Chakvetadze, Mumladze & Gabroshvili. The systematics of Hygromiidae, which was mainly based on a few characters of the dart apparatus of the genitalia, has long been controversial, especially the classification of some groups as subfamilies or tribes It had been revised in the past on several occasions (see references in Barker 1999) and continues to change as modern research methods and new data are made available (Neiber et al 2017, and references therein)

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