Alpheus angulosus McClure, is one of several species of snapping shrimp that live along the east coast of the United States and belong to the edwardsii group of Alpheus. The genus Alpheus presents with bilateral asymmetry in their chelipeds, specifically a large snapper and a smaller pincer. This is an extreme example of the asymmetry found in many other crustaceans. A significant amount of work has been done on the adult behavior, physiology, and transformation/regeneration of the two claws, but less is known about the early development of the nervous system that underlies this asymmetry. The work reported here begins to establish an atlas of embryonic development in this species staged by using both eye index and percent development connected to yolk depletion during embryogenesis. This represents the first step toward a more comprehensive understanding of embryonic development that can be used to address future neuro-developmental questions regarding limb asymmetry and plasticity.
Savant syndrome is a condition where prodigious talent co-occurs with developmental difficulties such as autism spectrum conditions (ASC). To better understand savant skills, we previously proposed a link with synaesthesia: that savant syndrome may arise in ASC individuals who also happen to have synaesthesia. A second, unrelated claim is that people with autism may have higher rates of synaesthesia. Here we ask whether synaesthesia is indeed found more often in autism per se, or only in cases where autism co-occurs with savant skills. People with autism in previous studies when tested for synaesthesia were not differentiated into those with and without savant abilities. Here we tested three groups: people with autism who also have savant skills (), people with autism without savant skills (), and controls without autism (). We used a validated test to diagnose grapheme–colour synaesthesia. Results show a significantly higher prevalence of synaesthesia in people with ASC, but only those who also have savant skills. This suggests that synaesthesia in autism is linked to those with savant abilities rather than autism per se. We discuss the role of synaesthesia in the development of prodigious talent.
Decades of studies have revealed the striking adaptations of avian brood parasites for their unique reproductive lifestyle. Several have reported that adult brood parasites sometimes kill host nestlings, although the reasons for this behaviour remain unclear. Using continuous video-recording and camera traps, we observed the same behaviour in the common cuckoo Cuculus canorus, showing that both host and parasite nestlings can be killed. The latter has never previously been observed in cuckoos. Here, we review this phenomenon and discuss possible explanations.