Corresponding author: Dmitry A. Sidorov (
Academic editor: O. Moldovan
A new species from the catacombs of Odessa (South Ukraine),
Sidorov DA, Kovtun OA (2015)
The area of the modern Black Sea was covered by Tethys Sea, which became isolated from other oceanic waters some 10–13 Myr ago. The predecessors of the Black Sea–Sarmatian, Meotian, Pontian, Ancient Euxininan, Karangatian, Neoeuxinian and other seas–were different in size, outline and salinity (
The territories surrounding the Black Sea are rich in terrestrial troglobionts (
Recent biological exploration of the subterranean waters in the catacombs located under the city of Odessa (Ukraine) have yielded a new species belonging to
The geological history of the Odessa limestone, its structure, karst, and the accumulation of the fossil remains in karst caves, as well as the catacombs themselves are detailed in the works of
Samples containing stygobionts were collected in the catacombs under Odessa (Figures
Map showing the distribution of the
Habitus of
Body length of the amphipods was recorded by holding the specimen straight and measuring the distance along the dorsal side of the body from the base of the first antenna to the base of the telson using a micrometer eyepiece in a Lomo MBS-9 dissecting microscope.
Appendages were drawn using a Carl Zeiss NU-2 compound microscope equipped with a drawing device as described in
In the descriptions, utilization of the descriptive term “defining angle” of the gnathopod propodi refers to the “angle” formed at the end of the palm and beginning of the posterior margin (see
The following description is based on the type series, and the material examined is deposited in the Zoological Museum of the Far East Federal University, Vladivostok, Russia (FEFU hereafter) and in the research collection of the Institute of Biology and Soil Science, Vladivostok, Russia (IBSS hereafter).
syn.:
Holotype: male, 11.5 mm, X42024/Cr-1541-FEFU, Ukraine, catacombs under Odessa, (depth -30 m from surface, lower level), Slobodka District (approx.
(not included in type series). All specimens measured, partially dissected and stored in different vials [17/3sd-IBSS]: 22 females (2×9.0 mm, 7×8.0 mm, 5×6.5 mm, 8×5.5 mm), 5 males (2×8.5 mm, 3×7.5), 7 juveniles, all with same data as type series.
Examined specimens have variations in setation of peduncular articles of pleopods, which can be naked or with single thin seta and bearing 5–6 retinacula (coupling setae) each. The ventral margin of epimera varies slightly in number of spines according to age and body size.
Among the eight known species of
Within the genus
Ukraine, catacombs under Odessa, Slobodka District [approx.
The epithet
All females of
Comparison of the morphological and ecological characteristics of defined groups of
Character | Character states | ||
---|---|---|---|
1Eyes | ommatidia reduced | well developed | entirely lost |
Antenna 1 / Body length ratio (males) | 0.60–0.90 | 0.45–0.60 | up to 0.30 |
Antenna 1 / Antenna 2 length ratio (males) | >2.0 | >1.33 | <=2.0 |
Calceoli | absent | present | ? |
Inferior antennal sinus | distinct | indistinct | indistinct |
Lower lip, inner lobes | broad | vestigial | vestigial |
Gnathopod 2 type, (palmar margin) | crangonyctid type |
synurellid type |
synurellid type |
Gnathopod 2, carpal lobe | narrow | broad | broad |
Number of pleopod retinacula | 4–6 | 2 | 2 |
Coxal plates 1-4 | shallow or deep | deep | deep |
Sexual dimorphism | Males larger than females | Females larger than males | ? |
Body length, mm | up to 13 | up to 10 | up to 6 |
Species | |||
Ecology | hypogean or spring inhabitants of karstic regions (preadapted stygobionts) | epigean inhabitants of coastal lowlands, stygophiles (crenobionts) | minute inhabitants of interstitial waters (stygobionts) |
1 Subspecific status has been assigned to blind and unpigmented subterranean populations of
The discovery of a new
The genus
According to
While we are able to identify species groups within
Characters of the
Considering the present distribution of the
We are thankful to Dr. K.K. Pronin, of the government organization The National Nature Geological Monument “Odessa Catacombs”, for access to the catacombs and remarks on the manuscript and to Dr. M.E. Daneliya (University of Helsinki, Finland) for assistance with various aspects of this study. We thank Dr. S.J. Taylor (University of Illinois, USA) for his comments on an earlier version and reviewing the English composition of the manuscript, and Dr. O. Moldovan and anonymous reviewers for providing valuable improvements.
Age determined by the outcropped stratified layers at localities with reference to RGRI (1983).