Ovarian Development and Larval Release of the Hermit Crab (Hilgendorf, 1879) (Decapoda: Anomura: Diogenidae) in Okinawa, Japan.

This study investigated ovarian development and larval release in the hermit crab , which inhabits the upper intertidal zone on Okinawa, Japan. Adult females were collected monthly and had a high gonadosomatic index (GSI) from May to October. Oocytes at vitellogenic stages were observed from May to October.

Food availability alters expression profiles of genes in relation to reproduction and nutrition in the females of tropical damselfish (Chrysiptera cyanea).

This study evaluated the effects of food availability on the transcript levels of genes related to reproduction and growth in the sapphire devil (Chrysiptera cyanea), a tropical damselfish. Nonbreeding fish were reared at high-food (HF) and low-food (LF) levels for 4 weeks under long-days. Vitellogenic oocytes could be observed in the ovaries of the HF group.

Involvement of melatonin in transducing moon-related signals into the reproductive network of the female honeycomb grouper Epinephelus merra.

Most groupers (genus Epinephelus) inhabiting tropical and subtropical waters exhibit lunar-related reproductive cycles. Their gametes develop synchronously toward and are released around the species-selected moon phase. Periodical changes in cues from the moon are likely used as zeitgeber, and the hypothalamic-pituitary-gonadal (HPG) axis may be activated after cues are perceived by the sensory organ and transduced as internal signals.

Daily expression of a clock gene in the brain and pituitary of the Malabar grouper (Epinephelus malabaricus).

Recent studies have revealed that, in addition to regulating the circadian system, clock genes such as cryptochrome (Cry) genes are involved in seasonal and lunar rhythmicity in fish. This study clarified the transcriptional characteristics of a Cry subtype (mgCry2) in the brain of the Malabar grouper, Epinephelus malabaricus, which is an important aquaculture species that spawns around the new moon. The cDNA sequence of mgCry2 showed high identity (97-99%) with fish Cry2 and had an open reading frame encoding a protein with 170 amino acids.

Changes in mRNA abundance of insulin-like growth factors in the brain and liver of a tropical damselfish, Chrysiptera cyanea, in relation to seasonal and food-manipulated reproduction.

Food availability can become a factor driving the reproductive activity of tropical fish, particularly when primary production within their habitats fluctuates with tropical monsoons. The present study examined the involvement of insulin-like growth factors (IGF) in controlling the reproduction of the sapphire devil Chrysiptera cyanea, a reef-associated damselfish that is capable of manipulating its reproductive activity based on food availability. We cloned and characterized the cDNAs of igf1 and igf2 and determined their transcript levels in relation to seasonal and food-manipulated reproduction.

Moonlight controls lunar-phase-dependency and regular oscillation of clock gene expressions in a lunar-synchronized spawner fish, Goldlined spinefoot.

Goldlined spinefoot, Siganus guttatus, inhabits tropical and subtropical waters and synchronizes its spawning around the first quarter moon likely using an hourglass-like lunar timer. In previous studies, we have found that clock genes (Cryptochrome3 and Period1) could play the role of state variable in the diencephalon when determining the lunar phase for spawning. Here, we identified three Cry, two Per, two Clock, and two Bmal genes in S.

Importance of sandy bottoms in coral reefs to the oscillation of daily rhythms in the tropical wrasse Halichoeres trimaculatus.

Most wrasse species swim during the day and bury themselves in the sandy bottoms of shallow reefs at night. This study aimed to evaluate the importance of sandy bottoms to the day-active/night-inactive rhythmicity of the tropical wrasse Halichoeres trimaculatus. Actogram analysis revealed that fish were active during the photophase and inactive during the scotophase in aquariums with both sandy and bare bottoms.

Hypothalamic expression and moonlight-independent changes of Cry3 and Per4 implicate their roles in lunar clock oscillators of the lunar-responsive Goldlined spinefoot.

Lunar cycle-associated physiology has been found in a wide variety of organisms. Studies suggest the presence of a circalunar clock in some animals, but the location of the lunar clock is unclear. We previously found lunar-associated expression of transcripts for Cryptochrome3 gene (SgCry3) in the brain of a lunar phase-responsive fish, the Goldlined spinefoot (Siganus guttatus).

Endogenous angiogenesis inhibitor vasohibin1 exhibits broad-spectrum antilymphangiogenic activity and suppresses lymph node metastasis.

During cancer progression, the angiogenesis that occurs is involved in tumor growth and hematogenous-distant metastasis, whereas lymphangiogenesis is involved in regional lymph node metastasis. Angiogenesis is counterregulated by various endogenous inhibitors; however, little is known about endogenous inhibitors of lymphangiogenesis. We recently isolated vasohibin1 as an angiogenesis inhibitor intrinsic to the endothelium and further demonstrated its anticancer activity through angiogenesis inhibition.