Bryocamptus (Rheocamptus) spinulosus Borutzky, 1934

Bryocamptus (Rheocamptus) spinulosus Borutzky, 1934

( Figs 21–25 View Figs 21–25 )

Location, ecology. Bryocamptus spinulosus was commonly found in many springs of the Knyszyn Primeval Forest Landscape Park (i.e. Pólko, Krzemianka, Dworzysk, Łaźnie) and in the rivers of Wigry National Park. Both female and male were detected.

Remarks. New species to the Polish fauna. Bryocamptus spinulosus is morphologically close to B. zschokkei (Schmeil, 1893) . The latter species is considered to be widely distributed in Poland, yet many records of B. zschokkei might in fact refer to B. spinulosus .

Gener al distrib utio n and biolo gy. The B. zschokkei group is widespread in Holarctic. The typical form of B. zschokkei is a cold-water stenothermal form, found in the littoral of alpine lakes or in cold springs and brooks. In lowland regions it is confined to cold springs, very close to their issue, where moist moss is its favorite habitat ( Borutzky 1952). Bryocamptus spinulosus has been reported from Slovakia, Czech Republic ( Sterba 1968), mountain brooks and springs in the North Caucasus ( Borutzky 1952), Albania and Bulgaria ( Apostolov 2004) and caves in NE Romania ( Meleg et al. 2011).

Distinguishing features. Bryocamptus spinulosus is morphologically very close to B. zschokkei . The Bryocamptus zschokkei group is highly variable. Differences from the typical form have been described by Schmeil, and relate to the armature of the body segments, limbs and even the number of leg segments. In B. spinulosus the swimming legs have the same segmentation pattern as what is observed in B. zschokkei group. The setal formula of leg 1−4 in the B. zschokkei group is as follows (according to Janetzky et al. 1996):

In the springs of Knyszyn Primaeval Forest B. spinulosus shows two-segmented endopodites in P2 and P3 ( Fig. 23 View Figs 21–25 ). The setal formula of leg 1−4 is as follows:

Basiendopodite and exopodite of P5 with 6 and 5 setae, respectively ( Fig. 25 View Figs 21–25 ). The structure of the inner apical caudal seta ( Fig. 22 View Figs 21–25 ) and P5 ( Fig. 25 View Figs 21–25 ) of the female are distinguish B. spinulosus from B. zschokkei . The inner apical caudal seta of B. spinulosus is serpentine-like with much widened base (Borutzky, 1934), which is very characteristics feature of this species. Caudal rami almost as long as wide ( Fig. 22 View Figs 21–25 ). Anal operculum with 4 large denticles ( Fig. 22 View Figs 21–25 ), which differs from the state (5 denticles) mentioned in the original description (Borutzky 1934). Antennule eight-segmented ( Fig. 24 View Figs 21–25 ).

Bryocamptus zschokkei zschokkei var. tatrensis , described by Minkiewicz (1916) from water bodies in the Tatra mountains and subsequently found in Lake Wigry and other parts of Poland, differ from B. spinulosus in few features only, i.e. differences in leg armature, row of spinules on the body segments ( Walter 2015).

Bryocamptus (Echinocamptus) echinatus (Mrázek, 1893) (Fig. 26)

Location, ecology. Bryocamptus echinatus was commonly found in springs of the Knyszyn Primaeval Forest Landscape Park, i.e. Dworzysk, Krzemianka, Łaźnie, Jałówka. Both females and males were detected.

G e n e r a l d i s t r i b u t i o n a n d b i o l o g y. Cold-water, European species, most frequently found in highland water bodies, rarely in cold spring in lowland regions ( Borutzky 1952). It has been recorded from lowland springs and rivers in Poland ( Drzycimski 1985) and Estonia ( Fefilova 2010).

D i s t i n g u i s h i n g f e a t u r e s. Caudal rami slightly longer than wide, tapering posteriorly. Oblique row of spinules present above bases of apical setae. Exopodites of P1 − P4 and endopodite of P1 three-segmented, endopodites of P2 – P4 two-segmented ( Borutzky 1952). P5 large and massive. Inner lobe of proximal segment of P5 markedly produced posteriorly with 5 setae of unequal length. Distal segment of P5 nearly oval-shaped with 5 setae (Fig. 26).