About Holothuria whitmaei Bell, 1887
Holothuria whitmaei Bell, 1887 is currently classified as a separate species from Holothuria nobilis; it was previously grouped within H. nobilis. Seasonal trends of two H. whitmaei populations, located at the Great Barrier Reef and Ningaloo Reef, have been investigated. Research found that the gonad index of this species peaks between April and June. Macroscopic and histological analysis confirmed that large germinal tubules, located centrally on the gonad base, progress through four distinct maturity stages: growing (II), mature (III), partly spawned (IV), and spent (V). One 2003 study recorded that up to 23% of H. whitmaei specimens remained hidden from some point during the night through midday, though the study was unable to explain this behavior. In another study focused on collecting ecological data for H. whitmaei, activity rates of marked specimens increased significantly in the initial hours after marking. This indicates that marking specimens likely compromises research results. A diurnal study of 30 black teat fish at Ningaloo Reef found that the proportion of sheltered (and therefore hidden, when viewed from directly above) animals was significantly greater in the morning compared to the afternoon. A separate study, which examined both marked and unmarked specimens, found that H. whitmaei are most active between 2:30 and 5:30 pm. Like many sea cucumbers, H. whitmaei is processed by drying and boiling to create beche-de-mar, a commercially valuable commodity that is important and profitable for many Pacific countries and communities, including Papua New Guinea, the Solomon Islands, Australia, and the Fiji Islands. H. whitmaei is among the highest value sea cucumber species for this trade; well-dried ‘A’ grade product can reach a price of $US 70–190 per kg, depending on size and quality. A moratorium implemented due to overharvesting has stopped exports from Papua New Guinea since 2009, while Fiji exports 243 tons of sea cucumber product per year.
