The Morphology and Some Data on the Anatomy of Pycnogonids of the Family Colossendeidae (Arthropoda: Chelicerata)

New findings and two new species of the genus Colossendeis Jarzynsky, 1870 (Pycnogonida, Colossendeidae), with a morphometric analysis for species from the Southern Ocean

“…The present specimens of C. scotti agree with the description provided by Calman (1915) and subsequent authors (Fry and Hedgpeth 1969;Pushkin 1993;Child 1995;Chimenz and Gravina 2001;Cano-Sánchez and López-González 2007;Alexeeva 2021). In fact, the measurements obtained from the holotype and our samples form a clearly defined group (Fig.…”

“…The specimens of C. drakei examined for this study agree with the description provided by Calman (1915) and subsequent authors (Fry and Hedgpeth 1969;Pushkin 1993;Child 1995;Alexeeva 2021). These authors did not indicate any special condition concerning the ovigeral claw, but Dietz et al (2015a) pointed out that the claw appears to be bifurcated.…”

Spawning and larval development of Colossendeis megalonyx, a giant Antarctic sea spider

“…During this grooming period the mass became compacted and firmly attached to the rock. We think the adult that tended the mass was male, and potentially the father, because it was one of the upper animals from the mating stack and because microscopic examination of cross sections of the adult's lower leg segments did not show the oocytes or the tissue of the vitellaria characteristic of female colossendeids (Alexeeva, 2021). Post‐spawning care of nonbrooded embryos in the Colossendeidae is an exciting finding because it may represent an evolutionarily intermediate strategy between free‐spawning and the paternal brooding exhibited by most other groups of sea spiders.…”