TY - JOUR AU - Schuster, Rolf AU - Greven, Hartmut PY - 2013/05/03 Y2 - 2024/03/29 TI - Reproductive traits of Macrobiotus hufelandi during a long-term field study with notes on Paramacrobiotus richtersi and Diphascon pingue (Eutardigrada) JF - Journal of Limnology JA - J Limnol VL - 72 IS - s1 SE - DO - 10.4081/jlimnol.2013.s1.e21 UR - https://www.jlimnol.it/jlimnol/article/view/jlimnol.2013.s1.e21 SP - e21 AB - We studied reproductive traits in populations of the eutardigrade species <em>Macrobiotus hufeland</em>i, <em>Paramacrobiotus richtersi</em>, and <em>Diphascon pingue</em> from a carpet of the moss <em>Rhytidiadelphus squarrosus</em> in the Black forest, Germany, over a period of 53 months. Specimens were fortnightly extracted, measured, and divided into dead and living individuals. The living specimens were divided into juveniles, ovigerous females (<em>i.e.</em> females with mature eggs and immature, but vitellogenetic eggs), and females with undifferentiated oocytes. Males were never found during the investigation period. For the most abundant species, <em>M. hufelandi</em>, it was shown that i) ovigerous females were found throughout the year; ii) reproductive activity (expressed as the percentage of ovigerous females in the total population) was highest from January to June, but peaks in these months varied considerably within the investigation period; iii) development of eggs may be considerably delayed compared with data obtained from cultures; iv) presence of ovigerous adults and juveniles was nearly opposite, <em>i.e.</em> the more adults the fewer juveniles were found, and a maximum of adults was followed by a maximum of juveniles with some delay and vice versa; v) number of oocytes, as well as length and percentage of ovigerous females relative to the total number of specimens appeared to be negatively correlated, whereas percentages of juveniles (&lt;260 μm in length) appeared to be positively correlated with temperature. Other correlations included humidity (number of oocytes, negative; percentage of juveniles, positive) and the sum of hours of sunshine (length and percentage of ovigerous females, negative; percentage of juveniles, positive). The relatively low numbers of <em>P. richtersi</em> and <em>D. pingue</em> collected during the investigation period did not allow a more detailed analysis, but here as well ovigerous females were found throughout the year. ER -